//===--- Driver.h - Clang GCC Compatible Driver -----------------*- 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

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_DRIVER_DRIVER_H

#define LLVM_CLANG_DRIVER_DRIVER_H

#include "clang/Basic/Diagnostic.h"

#include "clang/Basic/LLVM.h"

#include "clang/Driver/Action.h"

#include "clang/Driver/Options.h"

#include "clang/Driver/Phases.h"

#include "clang/Driver/ToolChain.h"

#include "clang/Driver/Types.h"

#include "clang/Driver/Util.h"

#include "llvm/ADT/StringMap.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Option/Arg.h"

#include "llvm/Option/ArgList.h"

#include "llvm/Support/StringSaver.h"

#include <list>

#include <map>

#include <string>

namespace llvm {

class Triple;

namespace vfs {

class FileSystem;

}

} // namespace llvm

namespace clang {

namespace driver {

  class Command;

  class Compilation;

  class InputInfo;

  class JobList;

  class JobAction;

  class SanitizerArgs;

  class ToolChain;

/// Describes the kind of LTO mode selected via -f(no-)?lto(=.*)? options.

enum LTOKind {

  LTOK_None,

  LTOK_Full,

  LTOK_Thin,

  LTOK_Unknown

};

/// Driver - Encapsulate logic for constructing compilation processes

/// from a set of gcc-driver-like command line arguments.

class Driver {

  DiagnosticsEngine &Diags;

  IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS;

  enum DriverMode {

    GCCMode,

    GXXMode,

    CPPMode,

    CLMode,

    FlangMode

  } Mode;

  enum SaveTempsMode {

    SaveTempsNone,

    SaveTempsCwd,

    SaveTempsObj

  } SaveTemps;

  enum BitcodeEmbedMode {

    EmbedNone,

    EmbedMarker,

    EmbedBitcode

  } BitcodeEmbed;

  /// LTO mode selected via -f(no-)?lto(=.*)? options.

  LTOKind LTOMode;

  /// LTO mode selected via -f(no-offload-)?lto(=.*)? options.

  LTOKind OffloadLTOMode;

public:

  enum OpenMPRuntimeKind {

    /// An unknown OpenMP runtime. We can't generate effective OpenMP code

    /// without knowing what runtime to target.

    OMPRT_Unknown,

    /// The LLVM OpenMP runtime. When completed and integrated, this will become

    /// the default for Clang.

    OMPRT_OMP,

    /// The GNU OpenMP runtime. Clang doesn't support generating OpenMP code for

    /// this runtime but can swallow the pragmas, and find and link against the

    /// runtime library itself.

    OMPRT_GOMP,

    /// The legacy name for the LLVM OpenMP runtime from when it was the Intel

    /// OpenMP runtime. We support this mode for users with existing

    /// dependencies on this runtime library name.

    OMPRT_IOMP5

  };

  // Diag - Forwarding function for diagnostics.

  DiagnosticBuilder Diag(unsigned DiagID) const {

    return Diags.Report(DiagID);

  }

  // FIXME: Privatize once interface is stable.

public:

  /// The name the driver was invoked as.

  std::string Name;

  /// The path the driver executable was in, as invoked from the

  /// command line.

  std::string Dir;

  /// The original path to the clang executable.

  std::string ClangExecutable;

  /// Target and driver mode components extracted from clang executable name.

  ParsedClangName ClangNameParts;

  /// The path to the installed clang directory, if any.

  std::string InstalledDir;

  /// The path to the compiler resource directory.

  std::string ResourceDir;

  /// System directory for config files.

  std::string SystemConfigDir;

  /// User directory for config files.

  std::string UserConfigDir;

  /// A prefix directory used to emulate a limited subset of GCC's '-Bprefix'

  /// functionality.

  /// FIXME: This type of customization should be removed in favor of the

  /// universal driver when it is ready.

  typedef SmallVector<std::string, 4> prefix_list;

  prefix_list PrefixDirs;

  /// sysroot, if present

  std::string SysRoot;

  /// Dynamic loader prefix, if present

  std::string DyldPrefix;

  /// Driver title to use with help.

  std::string DriverTitle;

  /// Information about the host which can be overridden by the user.

  std::string HostBits, HostMachine, HostSystem, HostRelease;

  /// The file to log CC_PRINT_PROC_STAT_FILE output to, if enabled.

  std::string CCPrintStatReportFilename;

  /// The file to log CC_PRINT_OPTIONS output to, if enabled.

  std::string CCPrintOptionsFilename;

  /// The file to log CC_PRINT_HEADERS output to, if enabled.

  std::string CCPrintHeadersFilename;

  /// The file to log CC_LOG_DIAGNOSTICS output to, if enabled.

  std::string CCLogDiagnosticsFilename;

  /// A list of inputs and their types for the given arguments.

  typedef SmallVector<std::pair<types::ID, const llvm::opt::Arg *>, 16>

      InputList;

  /// Whether the driver should follow g++ like behavior.

  bool CCCIsCXX() const { return Mode == GXXMode; }

  /// Whether the driver is just the preprocessor.

  bool CCCIsCPP() const { return Mode == CPPMode; }

  /// Whether the driver should follow gcc like behavior.

  bool CCCIsCC() const { return Mode == GCCMode; }

  /// Whether the driver should follow cl.exe like behavior.

  bool IsCLMode() const { return Mode == CLMode; }

  /// Whether the driver should invoke flang for fortran inputs.

  /// Other modes fall back to calling gcc which in turn calls gfortran.

  bool IsFlangMode() const { return Mode == FlangMode; }

  /// Only print tool bindings, don't build any jobs.

  unsigned CCCPrintBindings : 1;

  /// Set CC_PRINT_OPTIONS mode, which is like -v but logs the commands to

  /// CCPrintOptionsFilename or to stderr.

  unsigned CCPrintOptions : 1;

  /// Set CC_PRINT_HEADERS mode, which causes the frontend to log header include

  /// information to CCPrintHeadersFilename or to stderr.

  unsigned CCPrintHeaders : 1;

  /// Set CC_LOG_DIAGNOSTICS mode, which causes the frontend to log diagnostics

  /// to CCLogDiagnosticsFilename or to stderr, in a stable machine readable

  /// format.

  unsigned CCLogDiagnostics : 1;

  /// Whether the driver is generating diagnostics for debugging purposes.

  unsigned CCGenDiagnostics : 1;

  /// Set CC_PRINT_PROC_STAT mode, which causes the driver to dump

  /// performance report to CC_PRINT_PROC_STAT_FILE or to stdout.

  unsigned CCPrintProcessStats : 1;

  /// Pointer to the ExecuteCC1Tool function, if available.

  /// When the clangDriver lib is used through clang.exe, this provides a

  /// shortcut for executing the -cc1 command-line directly, in the same

  /// process.

  typedef int (*CC1ToolFunc)(SmallVectorImpl<const char *> &ArgV);

  CC1ToolFunc CC1Main = nullptr;

private:

  /// Raw target triple.

  std::string TargetTriple;

  /// Name to use when invoking gcc/g++.

  std::string CCCGenericGCCName;

  /// Name of configuration file if used.

  std::string ConfigFile;

  /// Allocator for string saver.

  llvm::BumpPtrAllocator Alloc;

  /// Object that stores strings read from configuration file.

  llvm::StringSaver Saver;

  /// Arguments originated from configuration file.

  std::unique_ptr<llvm::opt::InputArgList> CfgOptions;

  /// Arguments originated from command line.

  std::unique_ptr<llvm::opt::InputArgList> CLOptions;

  /// Whether to check that input files exist when constructing compilation

  /// jobs.

  unsigned CheckInputsExist : 1;

public:

  /// Force clang to emit reproducer for driver invocation. This is enabled

  /// indirectly by setting FORCE_CLANG_DIAGNOSTICS_CRASH environment variable

  /// or when using the -gen-reproducer driver flag.

  unsigned GenReproducer : 1;

  // getFinalPhase - Determine which compilation mode we are in and record

  // which option we used to determine the final phase.

  // TODO: Much of what getFinalPhase returns are not actually true compiler

  //       modes. Fold this functionality into Types::getCompilationPhases and

  //       handleArguments.

  phases::ID getFinalPhase(const llvm::opt::DerivedArgList &DAL,

                           llvm::opt::Arg **FinalPhaseArg = nullptr) const;

private:

  /// Certain options suppress the 'no input files' warning.

  unsigned SuppressMissingInputWarning : 1;

  /// Cache of all the ToolChains in use by the driver.

  ///

  /// This maps from the string representation of a triple to a ToolChain

  /// created targeting that triple. The driver owns all the ToolChain objects

  /// stored in it, and will clean them up when torn down.

  mutable llvm::StringMap<std::unique_ptr<ToolChain>> ToolChains;

private:

  /// TranslateInputArgs - Create a new derived argument list from the input

  /// arguments, after applying the standard argument translations.

  llvm::opt::DerivedArgList *

  TranslateInputArgs(const llvm::opt::InputArgList &Args) const;

  // handleArguments - All code related to claiming and printing diagnostics

  // related to arguments to the driver are done here.

  void handleArguments(Compilation &C, llvm::opt::DerivedArgList &Args,

                       const InputList &Inputs, ActionList &Actions) const;

  // Before executing jobs, sets up response files for commands that need them.

  void setUpResponseFiles(Compilation &C, Command &Cmd);

  void generatePrefixedToolNames(StringRef Tool, const ToolChain &TC,

                                 SmallVectorImpl<std::string> &Names) const;

  /// Find the appropriate .crash diagonostic file for the child crash

  /// under this driver and copy it out to a temporary destination with the

  /// other reproducer related files (.sh, .cache, etc). If not found, suggest a

  /// directory for the user to look at.

  ///

  /// \param ReproCrashFilename The file path to copy the .crash to.

  /// \param CrashDiagDir       The suggested directory for the user to look at

  ///                           in case the search or copy fails.

  ///

  /// \returns If the .crash is found and successfully copied return true,

  /// otherwise false and return the suggested directory in \p CrashDiagDir.

  bool getCrashDiagnosticFile(StringRef ReproCrashFilename,

                              SmallString<128> &CrashDiagDir);

public:

  /// Takes the path to a binary that's either in bin/ or lib/ and returns

  /// the path to clang's resource directory.

  static std::string GetResourcesPath(StringRef BinaryPath,

                                      StringRef CustomResourceDir = "");

  Driver(StringRef ClangExecutable, StringRef TargetTriple,

         DiagnosticsEngine &Diags, std::string Title = "clang LLVM compiler",

         IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS = nullptr);

  /// @name Accessors

  /// @{

  /// Name to use when invoking gcc/g++.

  const std::string &getCCCGenericGCCName() const { return CCCGenericGCCName; }

  const std::string &getConfigFile() const { return ConfigFile; }

  const llvm::opt::OptTable &getOpts() const { return getDriverOptTable(); }

  DiagnosticsEngine &getDiags() const { return Diags; }

  llvm::vfs::FileSystem &getVFS() const { return *VFS; }

  bool getCheckInputsExist() const { return CheckInputsExist; }

  void setCheckInputsExist(bool Value) { CheckInputsExist = Value; }

  void setTargetAndMode(const ParsedClangName &TM) { ClangNameParts = TM; }

  const std::string &getTitle() { return DriverTitle; }

  void setTitle(std::string Value) { DriverTitle = std::move(Value); }

  std::string getTargetTriple() const { return TargetTriple; }

  /// Get the path to the main clang executable.

  const char *getClangProgramPath() const {

    return ClangExecutable.c_str();

  }

  /// Get the path to where the clang executable was installed.

  const char *getInstalledDir() const {

    if (!InstalledDir.empty())

      return InstalledDir.c_str();

    return Dir.c_str();

  }

  void setInstalledDir(StringRef Value) { InstalledDir = std::string(Value); }

  bool isSaveTempsEnabled() const { return SaveTemps != SaveTempsNone; }

  bool isSaveTempsObj() const { return SaveTemps == SaveTempsObj; }

  bool embedBitcodeEnabled() const { return BitcodeEmbed != EmbedNone; }

  bool embedBitcodeInObject() const { return (BitcodeEmbed == EmbedBitcode); }

  bool embedBitcodeMarkerOnly() const { return (BitcodeEmbed == EmbedMarker); }

  /// Compute the desired OpenMP runtime from the flags provided.

  OpenMPRuntimeKind getOpenMPRuntime(const llvm::opt::ArgList &Args) const;

  /// @}

  /// @name Primary Functionality

  /// @{

  /// CreateOffloadingDeviceToolChains - create all the toolchains required to

  /// support offloading devices given the programming models specified in the

  /// current compilation. Also, update the host tool chain kind accordingly.

  void CreateOffloadingDeviceToolChains(Compilation &C, InputList &Inputs);

  /// BuildCompilation - Construct a compilation object for a command

  /// line argument vector.

  ///

  /// \return A compilation, or 0 if none was built for the given

  /// argument vector. A null return value does not necessarily

  /// indicate an error condition, the diagnostics should be queried

  /// to determine if an error occurred.

  Compilation *BuildCompilation(ArrayRef<const char *> Args);

  /// ParseArgStrings - Parse the given list of strings into an

  /// ArgList.

  llvm::opt::InputArgList ParseArgStrings(ArrayRef<const char *> Args,

                                          bool IsClCompatMode,

                                          bool &ContainsError);

  /// BuildInputs - Construct the list of inputs and their types from

  /// the given arguments.

  ///

  /// \param TC - The default host tool chain.

  /// \param Args - The input arguments.

  /// \param Inputs - The list to store the resulting compilation

  /// inputs onto.

  void BuildInputs(const ToolChain &TC, llvm::opt::DerivedArgList &Args,

                   InputList &Inputs) const;

  /// BuildActions - Construct the list of actions to perform for the

  /// given arguments, which are only done for a single architecture.

  ///

  /// \param C - The compilation that is being built.

  /// \param Args - The input arguments.

  /// \param Actions - The list to store the resulting actions onto.

  void BuildActions(Compilation &C, llvm::opt::DerivedArgList &Args,

                    const InputList &Inputs, ActionList &Actions) const;

  /// BuildUniversalActions - Construct the list of actions to perform

  /// for the given arguments, which may require a universal build.

  ///

  /// \param C - The compilation that is being built.

  /// \param TC - The default host tool chain.

  void BuildUniversalActions(Compilation &C, const ToolChain &TC,

                             const InputList &BAInputs) const;

  /// Check that the file referenced by Value exists. If it doesn't,

  /// issue a diagnostic and return false.

  /// If TypoCorrect is true and the file does not exist, see if it looks

  /// like a likely typo for a flag and if so print a "did you mean" blurb.

  bool DiagnoseInputExistence(const llvm::opt::DerivedArgList &Args,

                              StringRef Value, types::ID Ty,

                              bool TypoCorrect) const;

  /// BuildJobs - Bind actions to concrete tools and translate

  /// arguments to form the list of jobs to run.

  ///

  /// \param C - The compilation that is being built.

  void BuildJobs(Compilation &C) const;

  /// ExecuteCompilation - Execute the compilation according to the command line

  /// arguments and return an appropriate exit code.

  ///

  /// This routine handles additional processing that must be done in addition

  /// to just running the subprocesses, for example reporting errors, setting

  /// up response files, removing temporary files, etc.

  int ExecuteCompilation(Compilation &C,

     SmallVectorImpl< std::pair<int, const Command *> > &FailingCommands);

  /// Contains the files in the compilation diagnostic report generated by

  /// generateCompilationDiagnostics.

  struct CompilationDiagnosticReport {

    llvm::SmallVector<std::string, 4> TemporaryFiles;

  };

  /// generateCompilationDiagnostics - Generate diagnostics information

  /// including preprocessed source file(s).

  ///

  void generateCompilationDiagnostics(

      Compilation &C, const Command &FailingCommand,

      StringRef AdditionalInformation = "",

      CompilationDiagnosticReport *GeneratedReport = nullptr);

  /// @}

  /// @name Helper Methods

  /// @{

  /// PrintActions - Print the list of actions.

  void PrintActions(const Compilation &C) const;

  /// PrintHelp - Print the help text.

  ///

  /// \param ShowHidden - Show hidden options.

  void PrintHelp(bool ShowHidden) const;

  /// PrintVersion - Print the driver version.

  void PrintVersion(const Compilation &C, raw_ostream &OS) const;

  /// GetFilePath - Lookup \p Name in the list of file search paths.

  ///

  /// \param TC - The tool chain for additional information on

  /// directories to search.

  //

  // FIXME: This should be in CompilationInfo.

  std::string GetFilePath(StringRef Name, const ToolChain &TC) const;

  /// GetProgramPath - Lookup \p Name in the list of program search paths.

  ///

  /// \param TC - The provided tool chain for additional information on

  /// directories to search.

  //

  // FIXME: This should be in CompilationInfo.

  std::string GetProgramPath(StringRef Name, const ToolChain &TC) const;

  /// HandleAutocompletions - Handle --autocomplete by searching and printing

  /// possible flags, descriptions, and its arguments.

  void HandleAutocompletions(StringRef PassedFlags) const;

  /// HandleImmediateArgs - Handle any arguments which should be

  /// treated before building actions or binding tools.

  ///

  /// \return Whether any compilation should be built for this

  /// invocation.

  bool HandleImmediateArgs(const Compilation &C);

  /// ConstructAction - Construct the appropriate action to do for

  /// \p Phase on the \p Input, taking in to account arguments

  /// like -fsyntax-only or --analyze.

  Action *ConstructPhaseAction(

      Compilation &C, const llvm::opt::ArgList &Args, phases::ID Phase,

      Action *Input,

      Action::OffloadKind TargetDeviceOffloadKind = Action::OFK_None) const;

  /// BuildJobsForAction - Construct the jobs to perform for the action \p A and

  /// return an InputInfo for the result of running \p A.  Will only construct

  /// jobs for a given (Action, ToolChain, BoundArch, DeviceKind) tuple once.

  InputInfo

  BuildJobsForAction(Compilation &C, const Action *A, const ToolChain *TC,

                     StringRef BoundArch, bool AtTopLevel, bool MultipleArchs,

                     const char *LinkingOutput,

                     std::map<std::pair<const Action *, std::string>, InputInfo>

                         &CachedResults,

                     Action::OffloadKind TargetDeviceOffloadKind) const;

  /// Returns the default name for linked images (e.g., "a.out").

  const char *getDefaultImageName() const;

  /// GetNamedOutputPath - Return the name to use for the output of

  /// the action \p JA. The result is appended to the compilation's

  /// list of temporary or result files, as appropriate.

  ///

  /// \param C - The compilation.

  /// \param JA - The action of interest.

  /// \param BaseInput - The original input file that this action was

  /// triggered by.

  /// \param BoundArch - The bound architecture.

  /// \param AtTopLevel - Whether this is a "top-level" action.

  /// \param MultipleArchs - Whether multiple -arch options were supplied.

  /// \param NormalizedTriple - The normalized triple of the relevant target.

  const char *GetNamedOutputPath(Compilation &C, const JobAction &JA,

                                 const char *BaseInput, StringRef BoundArch,

                                 bool AtTopLevel, bool MultipleArchs,

                                 StringRef NormalizedTriple) const;

  /// GetTemporaryPath - Return the pathname of a temporary file to use

  /// as part of compilation; the file will have the given prefix and suffix.

  ///

  /// GCC goes to extra lengths here to be a bit more robust.

  std::string GetTemporaryPath(StringRef Prefix, StringRef Suffix) const;

  /// GetTemporaryDirectory - Return the pathname of a temporary directory to

  /// use as part of compilation; the directory will have the given prefix.

  std::string GetTemporaryDirectory(StringRef Prefix) const;

  /// Return the pathname of the pch file in clang-cl mode.

  std::string GetClPchPath(Compilation &C, StringRef BaseName) const;

  /// ShouldUseClangCompiler - Should the clang compiler be used to

  /// handle this action.

  bool ShouldUseClangCompiler(const JobAction &JA) const;

  /// ShouldUseFlangCompiler - Should the flang compiler be used to

  /// handle this action.

  bool ShouldUseFlangCompiler(const JobAction &JA) const;

  /// ShouldEmitStaticLibrary - Should the linker emit a static library.

  bool ShouldEmitStaticLibrary(const llvm::opt::ArgList &Args) const;

  /// Returns true if we are performing any kind of LTO.

  bool isUsingLTO(bool IsOffload = false) const {

    return getLTOMode(IsOffload) != LTOK_None;

  }

  /// Get the specific kind of LTO being performed.

  LTOKind getLTOMode(bool IsOffload = false) const {

    return IsOffload ? 
OffloadLTOMode211
 : 
LTOMode103k
;

  }

private:

  /// Tries to load options from configuration file.

  ///

  /// \returns true if error occurred.

  bool loadConfigFile();

  /// Read options from the specified file.

  ///

  /// \param [in] FileName File to read.

  /// \returns true, if error occurred while reading.

  bool readConfigFile(StringRef FileName);

  /// Set the driver mode (cl, gcc, etc) from the value of the `--driver-mode`

  /// option.

  void setDriverMode(StringRef DriverModeValue);

  /// Parse the \p Args list for LTO options and record the type of LTO

  /// compilation based on which -f(no-)?lto(=.*)? option occurs last.

  void setLTOMode(const llvm::opt::ArgList &Args);

  /// Retrieves a ToolChain for a particular \p Target triple.

  ///

  /// Will cache ToolChains for the life of the driver object, and create them

  /// on-demand.

  const ToolChain &getToolChain(const llvm::opt::ArgList &Args,

                                const llvm::Triple &Target) const;

  /// @}

  /// Retrieves a ToolChain for a particular device \p Target triple

  ///

  /// \param[in] HostTC is the host ToolChain paired with the device

  ///

  /// \param[in] Action (e.g. OFK_Cuda/OFK_OpenMP/OFK_SYCL) is an Offloading

  /// action that is optionally passed to a ToolChain (used by CUDA, to specify

  /// if it's used in conjunction with OpenMP)

  ///

  /// Will cache ToolChains for the life of the driver object, and create them

  /// on-demand.

  const ToolChain &getOffloadingDeviceToolChain(

      const llvm::opt::ArgList &Args, const llvm::Triple &Target,

      const ToolChain &HostTC,

      const Action::OffloadKind &TargetDeviceOffloadKind) const;

  /// Get bitmasks for which option flags to include and exclude based on

  /// the driver mode.

  std::pair<unsigned, unsigned> getIncludeExcludeOptionFlagMasks(bool IsClCompatMode) const;

  /// Helper used in BuildJobsForAction.  Doesn't use the cache when building

  /// jobs specifically for the given action, but will use the cache when

  /// building jobs for the Action's inputs.

  InputInfo BuildJobsForActionNoCache(

      Compilation &C, const Action *A, const ToolChain *TC, StringRef BoundArch,

      bool AtTopLevel, bool MultipleArchs, const char *LinkingOutput,

      std::map<std::pair<const Action *, std::string>, InputInfo>

          &CachedResults,

      Action::OffloadKind TargetDeviceOffloadKind) const;

public:

  /// GetReleaseVersion - Parse (([0-9]+)(.([0-9]+)(.([0-9]+)?))?)? and

  /// return the grouped values as integers. Numbers which are not

  /// provided are set to 0.

  ///

  /// \return True if the entire string was parsed (9.2), or all

  /// groups were parsed (10.3.5extrastuff). HadExtra is true if all

  /// groups were parsed but extra characters remain at the end.

  static bool GetReleaseVersion(StringRef Str, unsigned &Major, unsigned &Minor,

                                unsigned &Micro, bool &HadExtra);

  /// Parse digits from a string \p Str and fulfill \p Digits with

  /// the parsed numbers. This method assumes that the max number of

  /// digits to look for is equal to Digits.size().

  ///

  /// \return True if the entire string was parsed and there are

  /// no extra characters remaining at the end.

  static bool GetReleaseVersion(StringRef Str,

                                MutableArrayRef<unsigned> Digits);

  /// Compute the default -fmodule-cache-path.

  /// \return True if the system provides a default cache directory.

  static bool getDefaultModuleCachePath(SmallVectorImpl<char> &Result);

};

/// \return True if the last defined optimization level is -Ofast.

/// And False otherwise.

bool isOptimizationLevelFast(const llvm::opt::ArgList &Args);

/// \return True if the argument combination will end up generating remarks.

bool willEmitRemarks(const llvm::opt::ArgList &Args);

/// Returns the driver mode option's value, i.e. `X` in `--driver-mode=X`. If \p

/// Args doesn't mention one explicitly, tries to deduce from `ProgName`.

/// Returns empty on failure.

/// Common values are "gcc", "g++", "cpp", "cl" and "flang". Returned value need

/// not be one of these.

llvm::StringRef getDriverMode(StringRef ProgName, ArrayRef<const char *> Args);

/// Checks whether the value produced by getDriverMode is for CL mode.

bool IsClangCL(StringRef DriverMode);

} // end namespace driver

} // end namespace clang

#endif