Source/cmSystemTools.h - third_party/cmake - Git at Google

 /* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #ifndef cmSystemTools_h
 #define cmSystemTools_h

 #include "cmConfigure.h" // IWYU pragma: keep

 #include <cstddef>
 #include <functional>
 #include <string>
 #include <vector>

 #include <cm/string_view>

 #include "cmsys/Process.h"
 #include "cmsys/SystemTools.hxx" // IWYU pragma: export

 #include "cmCryptoHash.h"
 #include "cmDuration.h"
 #include "cmProcessOutput.h"

 /** \class cmSystemTools
  * \brief A collection of useful functions for CMake.
  *
  * cmSystemTools is a class that provides helper functions
  * for the CMake build system.
  */
 class cmSystemTools : public cmsys::SystemTools
 {
 public:
   using Superclass = cmsys::SystemTools;
   using Encoding = cmProcessOutput::Encoding;

   /**
    * Look for and replace registry values in a string
    */
   static void ExpandRegistryValues(std::string& source,
                                    KeyWOW64 view = KeyWOW64_Default);

   /** Map help document name to file name.  */
   static std::string HelpFileName(cm::string_view);

   using MessageCallback = std::function<void(const std::string&, const char*)>;
   /**
    *  Set the function used by GUIs to display error messages
    *  Function gets passed: message as a const char*,
    *  title as a const char*.
    */
   static void SetMessageCallback(MessageCallback f);

   /**
    * Display an error message.
    */
   static void Error(const std::string& m);

   /**
    * Display a message.
    */
   static void Message(const std::string& m, const char* title = nullptr);

   using OutputCallback = std::function<void(std::string const&)>;

   //! Send a string to stdout
   static void Stdout(const std::string& s);
   static void SetStdoutCallback(OutputCallback f);

   //! Send a string to stderr
   static void Stderr(const std::string& s);
   static void SetStderrCallback(OutputCallback f);

   using InterruptCallback = std::function<bool()>;
   static void SetInterruptCallback(InterruptCallback f);
   static bool GetInterruptFlag();

   //! Return true if there was an error at any point.
   static bool GetErrorOccuredFlag()
   {
     return cmSystemTools::s_ErrorOccured ||
       cmSystemTools::s_FatalErrorOccured || GetInterruptFlag();
   }
   //! If this is set to true, cmake stops processing commands.
   static void SetFatalErrorOccured()
   {
     cmSystemTools::s_FatalErrorOccured = true;
   }
   static void SetErrorOccured() { cmSystemTools::s_ErrorOccured = true; }
   //! Return true if there was an error at any point.
   static bool GetFatalErrorOccured()
   {
     return cmSystemTools::s_FatalErrorOccured || GetInterruptFlag();
   }

   //! Set the error occurred flag and fatal error back to false
   static void ResetErrorOccuredFlag()
   {
     cmSystemTools::s_FatalErrorOccured = false;
     cmSystemTools::s_ErrorOccured = false;
   }

   //! Return true if the path is a framework
   static bool IsPathToFramework(const std::string& value);

   static bool DoesFileExistWithExtensions(
     const std::string& name, const std::vector<std::string>& sourceExts);

   /**
    * Check if the given file exists in one of the parent directory of the
    * given file or directory and if it does, return the name of the file.
    * Toplevel specifies the top-most directory to where it will look.
    */
   static std::string FileExistsInParentDirectories(
     const std::string& fname, const std::string& directory,
     const std::string& toplevel);

   static void Glob(const std::string& directory, const std::string& regexp,
                    std::vector<std::string>& files);
   static void GlobDirs(const std::string& fullPath,
                        std::vector<std::string>& files);

   /**
    * Try to find a list of files that match the "simple" globbing
    * expression. At this point in time the globbing expressions have
    * to be in form: /directory/partial_file_name*. The * character has
    * to be at the end of the string and it does not support ?
    * []... The optional argument type specifies what kind of files you
    * want to find. 0 means all files, -1 means directories, 1 means
    * files only. This method returns true if search was successful.
    */
   static bool SimpleGlob(const std::string& glob,
                          std::vector<std::string>& files, int type = 0);

   /** Rename a file or directory within a single disk volume (atomic
       if possible).  */
   static bool RenameFile(const std::string& oldname,
                          const std::string& newname);

   //! Rename a file if contents are different, delete the source otherwise
   static void MoveFileIfDifferent(const std::string& source,
                                   const std::string& destination);

   //! Compute the hash of a file
   static std::string ComputeFileHash(const std::string& source,
                                      cmCryptoHash::Algo algo);

   /** Compute the md5sum of a string.  */
   static std::string ComputeStringMD5(const std::string& input);

   //! Get the SHA thumbprint for a certificate file
   static std::string ComputeCertificateThumbprint(const std::string& source);

   /**
    * Run a single executable command
    *
    * Output is controlled with outputflag. If outputflag is OUTPUT_NONE, no
    * user-viewable output from the program being run will be generated.
    * OUTPUT_MERGE is the legacy behaviour where stdout and stderr are merged
    * into stdout.  OUTPUT_FORWARD copies the output to stdout/stderr as
    * it was received.  OUTPUT_PASSTHROUGH passes through the original handles.
    *
    * If timeout is specified, the command will be terminated after
    * timeout expires. Timeout is specified in seconds.
    *
    * Argument retVal should be a pointer to the location where the
    * exit code will be stored. If the retVal is not specified and
    * the program exits with a code other than 0, then the this
    * function will return false.
    *
    * If the command has spaces in the path the caller MUST call
    * cmSystemTools::ConvertToRunCommandPath on the command before passing
    * it into this function or it will not work.  The command must be correctly
    * escaped for this to with spaces.
    */
   enum OutputOption
   {
     OUTPUT_NONE = 0,
     OUTPUT_MERGE,
     OUTPUT_FORWARD,
     OUTPUT_PASSTHROUGH
   };
   static bool RunSingleCommand(const std::string& command,
                                std::string* captureStdOut = nullptr,
                                std::string* captureStdErr = nullptr,
                                int* retVal = nullptr,
                                const char* dir = nullptr,
                                OutputOption outputflag = OUTPUT_MERGE,
                                cmDuration timeout = cmDuration::zero());
   /**
    * In this version of RunSingleCommand, command[0] should be
    * the command to run, and each argument to the command should
    * be in command[1]...command[command.size()]
    */
   static bool RunSingleCommand(std::vector<std::string> const& command,
                                std::string* captureStdOut = nullptr,
                                std::string* captureStdErr = nullptr,
                                int* retVal = nullptr,
                                const char* dir = nullptr,
                                OutputOption outputflag = OUTPUT_MERGE,
                                cmDuration timeout = cmDuration::zero(),
                                Encoding encoding = cmProcessOutput::Auto);

   static std::string PrintSingleCommand(std::vector<std::string> const&);

   /**
    * Parse arguments out of a single string command
    */
   static std::vector<std::string> ParseArguments(const std::string& command);

   /** Parse arguments out of a windows command line string.  */
   static void ParseWindowsCommandLine(const char* command,
                                       std::vector<std::string>& args);

   /** Parse arguments out of a unix command line string.  */
   static void ParseUnixCommandLine(const char* command,
                                    std::vector<std::string>& args);

   /** Split a command-line string into the parsed command and the unparsed
       arguments.  Returns false on unfinished quoting or escaping.  */
   static bool SplitProgramFromArgs(std::string const& command,
                                    std::string& program, std::string& args);

   /**
    * Handle response file in an argument list and return a new argument list
    * **/
   static std::vector<std::string> HandleResponseFile(
     std::vector<std::string>::const_iterator argBeg,
     std::vector<std::string>::const_iterator argEnd);

   static size_t CalculateCommandLineLengthLimit();

   static void DisableRunCommandOutput() { s_DisableRunCommandOutput = true; }
   static void EnableRunCommandOutput() { s_DisableRunCommandOutput = false; }
   static bool GetRunCommandOutput() { return s_DisableRunCommandOutput; }

   enum CompareOp
   {
     OP_EQUAL = 1,
     OP_LESS = 2,
     OP_GREATER = 4,
     OP_LESS_EQUAL = OP_LESS | OP_EQUAL,
     OP_GREATER_EQUAL = OP_GREATER | OP_EQUAL
   };

   /**
    * Compare versions
    */
   static bool VersionCompare(CompareOp op, const char* lhs, const char* rhs);
   static bool VersionCompareEqual(std::string const& lhs,
                                   std::string const& rhs);
   static bool VersionCompareGreater(std::string const& lhs,
                                     std::string const& rhs);
   static bool VersionCompareGreaterEq(std::string const& lhs,
                                       std::string const& rhs);

   /**
    * Compare two ASCII strings using natural versioning order.
    * Non-numerical characters are compared directly.
    * Numerical characters are first globbed such that, e.g.
    * `test000 < test01 < test0 < test1 < test10`.
    * Return a value less than, equal to, or greater than zero if lhs
    * precedes, equals, or succeeds rhs in the defined ordering.
    */
   static int strverscmp(std::string const& lhs, std::string const& rhs);

   /** Windows if this is true, the CreateProcess in RunCommand will
    *  not show new console windows when running programs.
    */
   static void SetRunCommandHideConsole(bool v) { s_RunCommandHideConsole = v; }
   static bool GetRunCommandHideConsole() { return s_RunCommandHideConsole; }
   /** Call cmSystemTools::Error with the message m, plus the
    * result of strerror(errno)
    */
   static void ReportLastSystemError(const char* m);

   /** a general output handler for cmsysProcess  */
   static int WaitForLine(cmsysProcess* process, std::string& line,
                          cmDuration timeout, std::vector<char>& out,
                          std::vector<char>& err);

   static void SetForceUnixPaths(bool v) { s_ForceUnixPaths = v; }
   static bool GetForceUnixPaths() { return s_ForceUnixPaths; }

   // ConvertToOutputPath use s_ForceUnixPaths
   static std::string ConvertToOutputPath(std::string const& path);
   static void ConvertToOutputSlashes(std::string& path);

   // ConvertToRunCommandPath does not use s_ForceUnixPaths and should
   // be used when RunCommand is called from cmake, because the
   // running cmake needs paths to be in its format
   static std::string ConvertToRunCommandPath(const std::string& path);

   /** compute the relative path from local to remote.  local must
       be a directory.  remote can be a file or a directory.
       Both remote and local must be full paths.  Basically, if
       you are in directory local and you want to access the file in remote
       what is the relative path to do that.  For example:
       /a/b/c/d to /a/b/c1/d1 -> ../../c1/d1
       from /usr/src to /usr/src/test/blah/foo.cpp -> test/blah/foo.cpp
   */
   static std::string RelativePath(std::string const& local,
                                   std::string const& remote);

   /**
    * Convert the given remote path to a relative path with respect to
    * the given local path.  Both paths must use forward slashes and not
    * already be escaped or quoted.
    */
   static std::string ForceToRelativePath(std::string const& local_path,
                                          std::string const& remote_path);

 #ifndef CMAKE_BOOTSTRAP
   /** Remove an environment variable */
   static bool UnsetEnv(const char* value);

   /** Get the list of all environment variables */
   static std::vector<std::string> GetEnvironmentVariables();

   /** Append multiple variables to the current environment. */
   static void AppendEnv(std::vector<std::string> const& env);

   /** Helper class to save and restore the environment.
       Instantiate this class as an automatic variable on
       the stack. Its constructor saves a copy of the current
       environment and then its destructor restores the
       original environment. */
   class SaveRestoreEnvironment
   {
   public:
     SaveRestoreEnvironment();
     ~SaveRestoreEnvironment();

     SaveRestoreEnvironment(SaveRestoreEnvironment const&) = delete;
     SaveRestoreEnvironment& operator=(SaveRestoreEnvironment const&) = delete;

   private:
     std::vector<std::string> Env;
   };
 #endif

   /** Setup the environment to enable VS 8 IDE output.  */
   static void EnableVSConsoleOutput();

   enum cmTarAction
   {
     TarActionCreate,
     TarActionList,
     TarActionExtract,
     TarActionNone
   };

   /** Create tar */
   enum cmTarCompression
   {
     TarCompressGZip,
     TarCompressBZip2,
     TarCompressXZ,
     TarCompressZstd,
     TarCompressNone
   };

   static bool ListTar(const std::string& outFileName,
                       const std::vector<std::string>& files, bool verbose);
   static bool CreateTar(const std::string& outFileName,
                         const std::vector<std::string>& files,
                         cmTarCompression compressType, bool verbose,
                         std::string const& mtime = std::string(),
                         std::string const& format = std::string());
   static bool ExtractTar(const std::string& inFileName,
                          const std::vector<std::string>& files, bool verbose);
   // This should be called first thing in main
   // it will keep child processes from inheriting the
   // stdin and stdout of this process.  This is important
   // if you want to be able to kill child processes and
   // not get stuck waiting for all the output on the pipes.
   static void DoNotInheritStdPipes();

   static void EnsureStdPipes();

   /** Random seed generation.  */
   static unsigned int RandomSeed();

   /** Find the directory containing CMake executables.  */
   static void FindCMakeResources(const char* argv0);

   /** Get the CMake resource paths, after FindCMakeResources.  */
   static std::string const& GetCTestCommand();
   static std::string const& GetCPackCommand();
   static std::string const& GetCMakeCommand();
   static std::string const& GetCMakeGUICommand();
   static std::string const& GetCMakeCursesCommand();
   static std::string const& GetCMClDepsCommand();
   static std::string const& GetCMakeRoot();

   /** Echo a message in color using KWSys's Terminal cprintf.  */
   static void MakefileColorEcho(int color, const char* message, bool newLine,
                                 bool enabled);

   /** Try to guess the soname of a shared library.  */
   static bool GuessLibrarySOName(std::string const& fullPath,
                                  std::string& soname);

   /** Try to guess the install name of a shared library.  */
   static bool GuessLibraryInstallName(std::string const& fullPath,
                                       std::string& soname);

   /** Try to set the RPATH in an ELF binary.  */
   static bool ChangeRPath(std::string const& file, std::string const& oldRPath,
                           std::string const& newRPath,
                           bool removeEnvironmentRPath,
                           std::string* emsg = nullptr,
                           bool* changed = nullptr);

   /** Try to remove the RPATH from an ELF binary.  */
   static bool RemoveRPath(std::string const& file, std::string* emsg = nullptr,
                           bool* removed = nullptr);

   /** Check whether the RPATH in an ELF binary contains the path
       given.  */
   static bool CheckRPath(std::string const& file, std::string const& newRPath);

   /** Remove a directory; repeat a few times in case of locked files.  */
   static bool RepeatedRemoveDirectory(const std::string& dir);

   /** Encode a string as a URL.  */
   static std::string EncodeURL(std::string const& in,
                                bool escapeSlashes = true);

 #ifdef _WIN32
   struct WindowsFileRetry
   {
     unsigned int Count;
     unsigned int Delay;
   };
   static WindowsFileRetry GetWindowsFileRetry();
 #endif

   /** Get the real path for a given path, removing all symlinks.
       This variant of GetRealPath also works on Windows but will
       resolve subst drives too.  */
   static std::string GetRealPathResolvingWindowsSubst(
     const std::string& path, std::string* errorMessage = nullptr);

   /** Perform one-time initialization of libuv.  */
   static void InitializeLibUV();

   /** Create a symbolic link if the platform supports it.  Returns whether
       creation succeeded. */
   static bool CreateSymlink(const std::string& origName,
                             const std::string& newName,
                             std::string* errorMessage = nullptr);

   /** Create a hard link if the platform supports it.  Returns whether
       creation succeeded. */
   static bool CreateLink(const std::string& origName,
                          const std::string& newName,
                          std::string* errorMessage = nullptr);

 private:
   static bool s_ForceUnixPaths;
   static bool s_RunCommandHideConsole;
   static bool s_ErrorOccured;
   static bool s_FatalErrorOccured;
   static bool s_DisableRunCommandOutput;
 };

 #endif
	/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
	file Copyright.txt or https://cmake.org/licensing for details. */
	#ifndef cmSystemTools_h
	#define cmSystemTools_h

	#include "cmConfigure.h" // IWYU pragma: keep

	#include <cstddef>
	#include <functional>
	#include <string>
	#include <vector>

	#include <cm/string_view>

	#include "cmsys/Process.h"
	#include "cmsys/SystemTools.hxx" // IWYU pragma: export

	#include "cmCryptoHash.h"
	#include "cmDuration.h"
	#include "cmProcessOutput.h"

	/** \class cmSystemTools
	* \brief A collection of useful functions for CMake.
	*
	* cmSystemTools is a class that provides helper functions
	* for the CMake build system.
	*/
	class cmSystemTools : public cmsys::SystemTools
	{
	public:
	using Superclass = cmsys::SystemTools;
	using Encoding = cmProcessOutput::Encoding;

	/**
	* Look for and replace registry values in a string
	*/
	static void ExpandRegistryValues(std::string& source,
	KeyWOW64 view = KeyWOW64_Default);

	/** Map help document name to file name. */
	static std::string HelpFileName(cm::string_view);

	using MessageCallback = std::function<void(const std::string&, const char*)>;
	/**
	* Set the function used by GUIs to display error messages
	* Function gets passed: message as a const char*,
	* title as a const char*.
	*/
	static void SetMessageCallback(MessageCallback f);

	/**
	* Display an error message.
	*/
	static void Error(const std::string& m);

	/**
	* Display a message.
	*/
	static void Message(const std::string& m, const char* title = nullptr);

	using OutputCallback = std::function<void(std::string const&)>;

	//! Send a string to stdout
	static void Stdout(const std::string& s);
	static void SetStdoutCallback(OutputCallback f);

	//! Send a string to stderr
	static void Stderr(const std::string& s);
	static void SetStderrCallback(OutputCallback f);

	using InterruptCallback = std::function<bool()>;
	static void SetInterruptCallback(InterruptCallback f);
	static bool GetInterruptFlag();

	//! Return true if there was an error at any point.
	static bool GetErrorOccuredFlag()
	{
	return cmSystemTools::s_ErrorOccured \|\|
	cmSystemTools::s_FatalErrorOccured \|\| GetInterruptFlag();
	}
	//! If this is set to true, cmake stops processing commands.
	static void SetFatalErrorOccured()
	{
	cmSystemTools::s_FatalErrorOccured = true;
	}
	static void SetErrorOccured() { cmSystemTools::s_ErrorOccured = true; }
	//! Return true if there was an error at any point.
	static bool GetFatalErrorOccured()
	{
	return cmSystemTools::s_FatalErrorOccured \|\| GetInterruptFlag();
	}

	//! Set the error occurred flag and fatal error back to false
	static void ResetErrorOccuredFlag()
	{
	cmSystemTools::s_FatalErrorOccured = false;
	cmSystemTools::s_ErrorOccured = false;
	}

	//! Return true if the path is a framework
	static bool IsPathToFramework(const std::string& value);

	static bool DoesFileExistWithExtensions(
	const std::string& name, const std::vector<std::string>& sourceExts);

	/**
	* Check if the given file exists in one of the parent directory of the
	* given file or directory and if it does, return the name of the file.
	* Toplevel specifies the top-most directory to where it will look.
	*/
	static std::string FileExistsInParentDirectories(
	const std::string& fname, const std::string& directory,
	const std::string& toplevel);

	static void Glob(const std::string& directory, const std::string& regexp,
	std::vector<std::string>& files);
	static void GlobDirs(const std::string& fullPath,
	std::vector<std::string>& files);

	/**
	* Try to find a list of files that match the "simple" globbing
	* expression. At this point in time the globbing expressions have
	* to be in form: /directory/partial_file_name. The character has
	* to be at the end of the string and it does not support ?
	* []... The optional argument type specifies what kind of files you
	* want to find. 0 means all files, -1 means directories, 1 means
	* files only. This method returns true if search was successful.
	*/
	static bool SimpleGlob(const std::string& glob,
	std::vector<std::string>& files, int type = 0);

	/** Rename a file or directory within a single disk volume (atomic
	if possible). */
	static bool RenameFile(const std::string& oldname,
	const std::string& newname);

	//! Rename a file if contents are different, delete the source otherwise
	static void MoveFileIfDifferent(const std::string& source,
	const std::string& destination);

	//! Compute the hash of a file
	static std::string ComputeFileHash(const std::string& source,
	cmCryptoHash::Algo algo);

	/** Compute the md5sum of a string. */
	static std::string ComputeStringMD5(const std::string& input);

	//! Get the SHA thumbprint for a certificate file
	static std::string ComputeCertificateThumbprint(const std::string& source);

	/**
	* Run a single executable command
	*
	* Output is controlled with outputflag. If outputflag is OUTPUT_NONE, no
	* user-viewable output from the program being run will be generated.
	* OUTPUT_MERGE is the legacy behaviour where stdout and stderr are merged
	* into stdout. OUTPUT_FORWARD copies the output to stdout/stderr as
	* it was received. OUTPUT_PASSTHROUGH passes through the original handles.
	*
	* If timeout is specified, the command will be terminated after
	* timeout expires. Timeout is specified in seconds.
	*
	* Argument retVal should be a pointer to the location where the
	* exit code will be stored. If the retVal is not specified and
	* the program exits with a code other than 0, then the this
	* function will return false.
	*
	* If the command has spaces in the path the caller MUST call
	* cmSystemTools::ConvertToRunCommandPath on the command before passing
	* it into this function or it will not work. The command must be correctly
	* escaped for this to with spaces.
	*/
	enum OutputOption
	{
	OUTPUT_NONE = 0,
	OUTPUT_MERGE,
	OUTPUT_FORWARD,
	OUTPUT_PASSTHROUGH
	};
	static bool RunSingleCommand(const std::string& command,
	std::string* captureStdOut = nullptr,
	std::string* captureStdErr = nullptr,
	int* retVal = nullptr,
	const char* dir = nullptr,
	OutputOption outputflag = OUTPUT_MERGE,
	cmDuration timeout = cmDuration::zero());
	/**
	* In this version of RunSingleCommand, command[0] should be
	* the command to run, and each argument to the command should
	* be in command[1]...command[command.size()]
	*/
	static bool RunSingleCommand(std::vector<std::string> const& command,
	std::string* captureStdOut = nullptr,
	std::string* captureStdErr = nullptr,
	int* retVal = nullptr,
	const char* dir = nullptr,
	OutputOption outputflag = OUTPUT_MERGE,
	cmDuration timeout = cmDuration::zero(),
	Encoding encoding = cmProcessOutput::Auto);

	static std::string PrintSingleCommand(std::vector<std::string> const&);

	/**
	* Parse arguments out of a single string command
	*/
	static std::vector<std::string> ParseArguments(const std::string& command);

	/** Parse arguments out of a windows command line string. */
	static void ParseWindowsCommandLine(const char* command,
	std::vector<std::string>& args);

	/** Parse arguments out of a unix command line string. */
	static void ParseUnixCommandLine(const char* command,
	std::vector<std::string>& args);

	/** Split a command-line string into the parsed command and the unparsed
	arguments. Returns false on unfinished quoting or escaping. */
	static bool SplitProgramFromArgs(std::string const& command,
	std::string& program, std::string& args);

	/**
	* Handle response file in an argument list and return a new argument list
	* **/
	static std::vector<std::string> HandleResponseFile(
	std::vector<std::string>::const_iterator argBeg,
	std::vector<std::string>::const_iterator argEnd);

	static size_t CalculateCommandLineLengthLimit();

	static void DisableRunCommandOutput() { s_DisableRunCommandOutput = true; }
	static void EnableRunCommandOutput() { s_DisableRunCommandOutput = false; }
	static bool GetRunCommandOutput() { return s_DisableRunCommandOutput; }

	enum CompareOp
	{
	OP_EQUAL = 1,
	OP_LESS = 2,
	OP_GREATER = 4,
	OP_LESS_EQUAL = OP_LESS \| OP_EQUAL,
	OP_GREATER_EQUAL = OP_GREATER \| OP_EQUAL
	};

	/**
	* Compare versions
	*/
	static bool VersionCompare(CompareOp op, const char* lhs, const char* rhs);
	static bool VersionCompareEqual(std::string const& lhs,
	std::string const& rhs);
	static bool VersionCompareGreater(std::string const& lhs,
	std::string const& rhs);
	static bool VersionCompareGreaterEq(std::string const& lhs,
	std::string const& rhs);

	/**
	* Compare two ASCII strings using natural versioning order.
	* Non-numerical characters are compared directly.
	* Numerical characters are first globbed such that, e.g.
	* `test000 < test01 < test0 < test1 < test10`.
	* Return a value less than, equal to, or greater than zero if lhs
	* precedes, equals, or succeeds rhs in the defined ordering.
	*/
	static int strverscmp(std::string const& lhs, std::string const& rhs);

	/** Windows if this is true, the CreateProcess in RunCommand will
	* not show new console windows when running programs.
	*/
	static void SetRunCommandHideConsole(bool v) { s_RunCommandHideConsole = v; }
	static bool GetRunCommandHideConsole() { return s_RunCommandHideConsole; }
	/** Call cmSystemTools::Error with the message m, plus the
	* result of strerror(errno)
	*/
	static void ReportLastSystemError(const char* m);

	/** a general output handler for cmsysProcess */
	static int WaitForLine(cmsysProcess* process, std::string& line,
	cmDuration timeout, std::vector<char>& out,
	std::vector<char>& err);

	static void SetForceUnixPaths(bool v) { s_ForceUnixPaths = v; }
	static bool GetForceUnixPaths() { return s_ForceUnixPaths; }

	// ConvertToOutputPath use s_ForceUnixPaths
	static std::string ConvertToOutputPath(std::string const& path);
	static void ConvertToOutputSlashes(std::string& path);

	// ConvertToRunCommandPath does not use s_ForceUnixPaths and should
	// be used when RunCommand is called from cmake, because the
	// running cmake needs paths to be in its format
	static std::string ConvertToRunCommandPath(const std::string& path);

	/** compute the relative path from local to remote. local must
	be a directory. remote can be a file or a directory.
	Both remote and local must be full paths. Basically, if
	you are in directory local and you want to access the file in remote
	what is the relative path to do that. For example:
	/a/b/c/d to /a/b/c1/d1 -> ../../c1/d1
	from /usr/src to /usr/src/test/blah/foo.cpp -> test/blah/foo.cpp
	*/
	static std::string RelativePath(std::string const& local,
	std::string const& remote);

	/**
	* Convert the given remote path to a relative path with respect to
	* the given local path. Both paths must use forward slashes and not
	* already be escaped or quoted.
	*/
	static std::string ForceToRelativePath(std::string const& local_path,
	std::string const& remote_path);

	#ifndef CMAKE_BOOTSTRAP
	/** Remove an environment variable */
	static bool UnsetEnv(const char* value);

	/** Get the list of all environment variables */
	static std::vector<std::string> GetEnvironmentVariables();

	/** Append multiple variables to the current environment. */
	static void AppendEnv(std::vector<std::string> const& env);

	/** Helper class to save and restore the environment.
	Instantiate this class as an automatic variable on
	the stack. Its constructor saves a copy of the current
	environment and then its destructor restores the
	original environment. */
	class SaveRestoreEnvironment
	{
	public:
	SaveRestoreEnvironment();
	~SaveRestoreEnvironment();

	SaveRestoreEnvironment(SaveRestoreEnvironment const&) = delete;
	SaveRestoreEnvironment& operator=(SaveRestoreEnvironment const&) = delete;

	private:
	std::vector<std::string> Env;
	};
	#endif

	/** Setup the environment to enable VS 8 IDE output. */
	static void EnableVSConsoleOutput();

	enum cmTarAction
	{
	TarActionCreate,
	TarActionList,
	TarActionExtract,
	TarActionNone
	};

	/** Create tar */
	enum cmTarCompression
	{
	TarCompressGZip,
	TarCompressBZip2,
	TarCompressXZ,
	TarCompressZstd,
	TarCompressNone
	};

	static bool ListTar(const std::string& outFileName,
	const std::vector<std::string>& files, bool verbose);
	static bool CreateTar(const std::string& outFileName,
	const std::vector<std::string>& files,
	cmTarCompression compressType, bool verbose,
	std::string const& mtime = std::string(),
	std::string const& format = std::string());
	static bool ExtractTar(const std::string& inFileName,
	const std::vector<std::string>& files, bool verbose);
	// This should be called first thing in main
	// it will keep child processes from inheriting the
	// stdin and stdout of this process. This is important
	// if you want to be able to kill child processes and
	// not get stuck waiting for all the output on the pipes.
	static void DoNotInheritStdPipes();

	static void EnsureStdPipes();

	/** Random seed generation. */
	static unsigned int RandomSeed();

	/** Find the directory containing CMake executables. */
	static void FindCMakeResources(const char* argv0);

	/** Get the CMake resource paths, after FindCMakeResources. */
	static std::string const& GetCTestCommand();
	static std::string const& GetCPackCommand();
	static std::string const& GetCMakeCommand();
	static std::string const& GetCMakeGUICommand();
	static std::string const& GetCMakeCursesCommand();
	static std::string const& GetCMClDepsCommand();
	static std::string const& GetCMakeRoot();

	/** Echo a message in color using KWSys's Terminal cprintf. */
	static void MakefileColorEcho(int color, const char* message, bool newLine,
	bool enabled);

	/** Try to guess the soname of a shared library. */
	static bool GuessLibrarySOName(std::string const& fullPath,
	std::string& soname);

	/** Try to guess the install name of a shared library. */
	static bool GuessLibraryInstallName(std::string const& fullPath,
	std::string& soname);

	/** Try to set the RPATH in an ELF binary. */
	static bool ChangeRPath(std::string const& file, std::string const& oldRPath,
	std::string const& newRPath,
	bool removeEnvironmentRPath,
	std::string* emsg = nullptr,
	bool* changed = nullptr);

	/** Try to remove the RPATH from an ELF binary. */
	static bool RemoveRPath(std::string const& file, std::string* emsg = nullptr,
	bool* removed = nullptr);

	/** Check whether the RPATH in an ELF binary contains the path
	given. */
	static bool CheckRPath(std::string const& file, std::string const& newRPath);

	/** Remove a directory; repeat a few times in case of locked files. */
	static bool RepeatedRemoveDirectory(const std::string& dir);

	/** Encode a string as a URL. */
	static std::string EncodeURL(std::string const& in,
	bool escapeSlashes = true);

	#ifdef _WIN32
	struct WindowsFileRetry
	{
	unsigned int Count;
	unsigned int Delay;
	};
	static WindowsFileRetry GetWindowsFileRetry();
	#endif

	/** Get the real path for a given path, removing all symlinks.
	This variant of GetRealPath also works on Windows but will
	resolve subst drives too. */
	static std::string GetRealPathResolvingWindowsSubst(
	const std::string& path, std::string* errorMessage = nullptr);

	/** Perform one-time initialization of libuv. */
	static void InitializeLibUV();

	/** Create a symbolic link if the platform supports it. Returns whether
	creation succeeded. */
	static bool CreateSymlink(const std::string& origName,
	const std::string& newName,
	std::string* errorMessage = nullptr);

	/** Create a hard link if the platform supports it. Returns whether
	creation succeeded. */
	static bool CreateLink(const std::string& origName,
	const std::string& newName,
	std::string* errorMessage = nullptr);

	private:
	static bool s_ForceUnixPaths;
	static bool s_RunCommandHideConsole;
	static bool s_ErrorOccured;
	static bool s_FatalErrorOccured;
	static bool s_DisableRunCommandOutput;
	};

	#endif