Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- llvm/Support/Program.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 declares the llvm::sys::Program class.

//

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

#ifndef LLVM_SUPPORT_PROGRAM_H

#define LLVM_SUPPORT_PROGRAM_H

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Config/llvm-config.h"

#include "llvm/Support/ErrorOr.h"

#include "llvm/Support/FileSystem.h"

#include <chrono>

#include <optional>

#include <system_error>

namespace llvm {

class BitVector;

namespace sys {

  /// This is the OS-specific separator for PATH like environment variables:

  // a colon on Unix or a semicolon on Windows.

#if defined(LLVM_ON_UNIX)

  const char EnvPathSeparator = ':';

#elif defined (_WIN32)

  const char EnvPathSeparator = ';';

#endif

#if defined(_WIN32)

  typedef unsigned long procid_t; // Must match the type of DWORD on Windows.

  typedef void *process_t;        // Must match the type of HANDLE on Windows.

#else

  typedef ::pid_t procid_t;

  typedef procid_t process_t;

#endif

  /// This struct encapsulates information about a process.

  struct ProcessInfo {

    enum : procid_t { InvalidPid = 0 };

    procid_t Pid;      /// The process identifier.

    process_t Process; /// Platform-dependent process object.

    /// The return code, set after execution.

    int ReturnCode;

    ProcessInfo();

  };

  /// This struct encapsulates information about a process execution.

  struct ProcessStatistics {

    std::chrono::microseconds TotalTime;

    std::chrono::microseconds UserTime;

    uint64_t PeakMemory = 0; ///< Maximum resident set size in KiB.

  };

  /// Find the first executable file \p Name in \p Paths.

  ///

  /// This does not perform hashing as a shell would but instead stats each PATH

  /// entry individually so should generally be avoided. Core LLVM library

  /// functions and options should instead require fully specified paths.

  ///

  /// \param Name name of the executable to find. If it contains any system

  ///   slashes, it will be returned as is.

  /// \param Paths optional list of paths to search for \p Name. If empty it

  ///   will use the system PATH environment instead.

  ///

  /// \returns The fully qualified path to the first \p Name in \p Paths if it

  ///   exists. \p Name if \p Name has slashes in it. Otherwise an error.

  ErrorOr<std::string>

  findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {});

  // These functions change the specified standard stream (stdin or stdout) mode

  // based on the Flags. They return errc::success if the specified stream was

  // changed. Otherwise, a platform dependent error is returned.

  std::error_code ChangeStdinMode(fs::OpenFlags Flags);

  std::error_code ChangeStdoutMode(fs::OpenFlags Flags);

  // These functions change the specified standard stream (stdin or stdout) to

  // binary mode. They return errc::success if the specified stream

  // was changed. Otherwise a platform dependent error is returned.

  std::error_code ChangeStdinToBinary();

  std::error_code ChangeStdoutToBinary();

  /// This function executes the program using the arguments provided.  The

  /// invoked program will inherit the stdin, stdout, and stderr file

  /// descriptors, the environment and other configuration settings of the

  /// invoking program.

  /// This function waits for the program to finish, so should be avoided in

  /// library functions that aren't expected to block. Consider using

  /// ExecuteNoWait() instead.

  /// \returns an integer result code indicating the status of the program.

  /// A zero or positive value indicates the result code of the program.

  /// -1 indicates failure to execute

  /// -2 indicates a crash during execution or timeout

  int ExecuteAndWait(

      StringRef Program, ///< Path of the program to be executed. It is

      ///< presumed this is the result of the findProgramByName method.

      ArrayRef<StringRef> Args, ///< An array of strings that are passed to the

      ///< program.  The first element should be the name of the program.

      ///< The array should **not** be terminated by an empty StringRef.

      std::optional<ArrayRef<StringRef>> Env =

          std::nullopt, ///< An optional vector of

      ///< strings to use for the program's environment. If not provided, the

      ///< current program's environment will be used.  If specified, the

      ///< vector should **not** be terminated by an empty StringRef.

      ArrayRef<std::optional<StringRef>> Redirects = {}, ///<

      ///< An array of optional paths. Should have a size of zero or three.

      ///< If the array is empty, no redirections are performed.

      ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2)

      ///< will be redirected to the corresponding paths, if the optional path

      ///< is present (not \c std::nullopt).

      ///< When an empty path is passed in, the corresponding file descriptor

      ///< will be disconnected (ie, /dev/null'd) in a portable way.

      unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount

      ///< of time to wait for the child process to exit. If the time

      ///< expires, the child is killed and this call returns. If zero,

      ///< this function will wait until the child finishes or forever if

      ///< it doesn't.

      unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount

      ///< of memory can be allocated by process. If memory usage will be

      ///< higher limit, the child is killed and this call returns. If zero

      ///< - no memory limit.

      std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a

      ///< string instance in which error messages will be returned. If the

      ///< string is non-empty upon return an error occurred while invoking the

      ///< program.

      bool *ExecutionFailed = nullptr,

      std::optional<ProcessStatistics> *ProcStat = nullptr, ///< If non-zero,

      /// provides a pointer to a structure in which process execution

      /// statistics will be stored.

      BitVector *AffinityMask = nullptr ///< CPUs or processors the new

                                        /// program shall run on.

  );

  /// Similar to ExecuteAndWait, but returns immediately.

  /// @returns The \see ProcessInfo of the newly launched process.

  /// \note On Microsoft Windows systems, users will need to either call

  /// \see Wait until the process finished execution or win32 CloseHandle() API

  /// on ProcessInfo.ProcessHandle to avoid memory leaks.

  ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef<StringRef> Args,

                            std::optional<ArrayRef<StringRef>> Env,

                            ArrayRef<std::optional<StringRef>> Redirects = {},

                            unsigned MemoryLimit = 0,

                            std::string *ErrMsg = nullptr,

                            bool *ExecutionFailed = nullptr,

                            BitVector *AffinityMask = nullptr);

  /// Return true if the given arguments fit within system-specific

  /// argument length limits.

  bool commandLineFitsWithinSystemLimits(StringRef Program,

                                         ArrayRef<StringRef> Args);

  /// Return true if the given arguments fit within system-specific

  /// argument length limits.

  bool commandLineFitsWithinSystemLimits(StringRef Program,

                                         ArrayRef<const char *> Args);

  /// File encoding options when writing contents that a non-UTF8 tool will

  /// read (on Windows systems). For UNIX, we always use UTF-8.

  enum WindowsEncodingMethod {

    /// UTF-8 is the LLVM native encoding, being the same as "do not perform

    /// encoding conversion".

    WEM_UTF8,

    WEM_CurrentCodePage,

    WEM_UTF16

  };

  /// Saves the UTF8-encoded \p contents string into the file \p FileName

  /// using a specific encoding.

  ///

  /// This write file function adds the possibility to choose which encoding

  /// to use when writing a text file. On Windows, this is important when

  /// writing files with internationalization support with an encoding that is

  /// different from the one used in LLVM (UTF-8). We use this when writing

  /// response files, since GCC tools on MinGW only understand legacy code

  /// pages, and VisualStudio tools only understand UTF-16.

  /// For UNIX, using different encodings is silently ignored, since all tools

  /// work well with UTF-8.

  /// This function assumes that you only use UTF-8 *text* data and will convert

  /// it to your desired encoding before writing to the file.

  ///

  /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in

  /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is

  /// our best shot to make gcc/ld understand international characters. This

  /// should be changed as soon as binutils fix this to support UTF16 on mingw.

  ///

  /// \returns non-zero error_code if failed

  std::error_code

  writeFileWithEncoding(StringRef FileName, StringRef Contents,

                        WindowsEncodingMethod Encoding = WEM_UTF8);

  /// This function waits for the process specified by \p PI to finish.

  /// \returns A \see ProcessInfo struct with Pid set to:

  /// \li The process id of the child process if the child process has changed

  /// state.

  /// \li 0 if the child process has not changed state.

  /// \note Users of this function should always check the ReturnCode member of

  /// the \see ProcessInfo returned from this function.

  ProcessInfo

  Wait(const ProcessInfo &PI, ///< The child process that should be waited on.

       std::optional<unsigned> SecondsToWait, ///< If std::nullopt, waits until

       ///< child has terminated.

       ///< If a value, this specifies the amount of time to wait for the child

       ///< process. If the time expires, and \p Polling is false, the child is

       ///< killed and this < function returns. If the time expires and \p

       ///< Polling is true, the child is resumed.

       ///<

       ///< If zero, this function will perform a non-blocking

       ///< wait on the child process.

       std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a

       ///< string instance in which error messages will be returned. If the

       ///< string is non-empty upon return an error occurred while invoking the

       ///< program.

       std::optional<ProcessStatistics> *ProcStat =

           nullptr, ///< If non-zero, provides

       /// a pointer to a structure in which process execution statistics will

       /// be stored.

       bool Polling = false ///< If true, do not kill the process on timeout.

  );

  /// Print a command argument, and optionally quote it.

  void printArg(llvm::raw_ostream &OS, StringRef Arg, bool Quote);

#if defined(_WIN32)

  /// Given a list of command line arguments, quote and escape them as necessary

  /// to build a single flat command line appropriate for calling CreateProcess

  /// on

  /// Windows.

  ErrorOr<std::wstring> flattenWindowsCommandLine(ArrayRef<StringRef> Args);

#endif

  }

}

#endif