include/llvm/Support/Program.h - llvm - Git at Google

 //===- llvm/Support/Program.h ------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the llvm::sys::Program class.
 //
 //===----------------------------------------------------------------------===//

 #ifndef LLVM_SYSTEM_PROGRAM_H
 #define LLVM_SYSTEM_PROGRAM_H

 #include "llvm/Support/Path.h"

 namespace llvm {
 namespace sys {

   // TODO: Add operations to communicate with the process, redirect its I/O,
   // etc.

   /// This class provides an abstraction for programs that are executable by the
   /// operating system. It provides a platform generic way to find executable
   /// programs from the path and to execute them in various ways. The sys::Path
   /// class is used to specify the location of the Program.
   /// @since 1.4
   /// @brief An abstraction for finding and executing programs.
   class Program {
     /// Opaque handle for target specific data.
     void *Data_;

     // Noncopyable.
     Program(const Program& other);
     Program& operator=(const Program& other);

     /// @name Methods
     /// @{
   public:

     Program();
     ~Program();

     /// Return process ID of this program.
     unsigned GetPid() const;

     /// This function executes the program using the \p arguments provided.  The
     /// invoked program will inherit the stdin, stdout, and stderr file
     /// descriptors, the environment and other configuration settings of the
     /// invoking program. If Path::executable() does not return true when this
     /// function is called then a std::string is thrown.
     /// @returns false in case of error, true otherwise.
     /// @see FindProgramByName
     /// @brief Executes the program with the given set of \p args.
     bool Execute
     ( const Path& path,  ///< sys::Path object providing the path of the
       ///< program to be executed. It is presumed this is the result of
       ///< the FindProgramByName method.
       const char** args, ///< A vector of strings that are passed to the
       ///< program.  The first element should be the name of the program.
       ///< The list *must* be terminated by a null char* entry.
       const char ** env = 0, ///< An optional vector of strings to use for
       ///< the program's environment. If not provided, the current program's
       ///< environment will be used.
       const sys::Path** redirects = 0, ///< An optional array of pointers to
       ///< Paths. If the array is null, no redirection is done. The array
       ///< should have a size of at least three. If the pointer in the array
       ///< are not null, then the inferior process's stdin(0), stdout(1),
       ///< and stderr(2) will be redirected to the corresponding Paths.
       ///< When an empty Path is passed in, the corresponding file
       ///< descriptor will be disconnected (ie, /dev/null'd) in a portable
       ///< way.
       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 = 0 ///< 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.
       );

     /// This function waits for the program to exit. This function will block
     /// the current program until the invoked program exits.
     /// @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
     /// @see Execute
     /// @brief Waits for the program to exit.
     int Wait
     ( const Path& path, ///< The path to the child process executable.
       unsigned secondsToWait, ///< 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.
       std::string* ErrMsg ///< 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 waiting.
       );

     /// This function terminates the program.
     /// @returns true if an error occurred.
     /// @see Execute
     /// @brief Terminates the program.
     bool Kill
     ( std::string* ErrMsg = 0 ///< 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 killing the
       ///< program.
       );

     /// This static constructor (factory) will attempt to locate a program in
     /// the operating system's file system using some pre-determined set of
     /// locations to search (e.g. the PATH on Unix). Paths with slashes are
     /// returned unmodified.
     /// @returns A Path object initialized to the path of the program or a
     /// Path object that is empty (invalid) if the program could not be found.
     /// @brief Construct a Program by finding it by name.
     static Path FindProgramByName(const std::string& name);

     // These methods change the specified standard stream (stdin,
     // stdout, or stderr) to binary mode. They return true if an error
     // occurred
     static bool ChangeStdinToBinary();
     static bool ChangeStdoutToBinary();
     static bool ChangeStderrToBinary();

     /// A convenience function equivalent to Program prg; prg.Execute(..);
     /// prg.Wait(..);
     /// @see Execute, Wait
     static int ExecuteAndWait(const Path& path,
                               const char** args,
                               const char ** env = 0,
                               const sys::Path** redirects = 0,
                               unsigned secondsToWait = 0,
                               unsigned memoryLimit = 0,
                               std::string* ErrMsg = 0);

     /// A convenience function equivalent to Program prg; prg.Execute(..);
     /// @see Execute
     static void ExecuteNoWait(const Path& path,
                               const char** args,
                               const char ** env = 0,
                               const sys::Path** redirects = 0,
                               unsigned memoryLimit = 0,
                               std::string* ErrMsg = 0);

     /// @}

   };
 }
 }

 #endif
	//===- llvm/Support/Program.h ------------------------------------- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file declares the llvm::sys::Program class.
	//
	//===----------------------------------------------------------------------===//

	#ifndef LLVM_SYSTEM_PROGRAM_H
	#define LLVM_SYSTEM_PROGRAM_H

	#include "llvm/Support/Path.h"

	namespace llvm {
	namespace sys {

	// TODO: Add operations to communicate with the process, redirect its I/O,
	// etc.

	/// This class provides an abstraction for programs that are executable by the
	/// operating system. It provides a platform generic way to find executable
	/// programs from the path and to execute them in various ways. The sys::Path
	/// class is used to specify the location of the Program.
	/// @since 1.4
	/// @brief An abstraction for finding and executing programs.
	class Program {
	/// Opaque handle for target specific data.
	void *Data_;

	// Noncopyable.
	Program(const Program& other);
	Program& operator=(const Program& other);

	/// @name Methods
	/// @{
	public:

	Program();
	~Program();

	/// Return process ID of this program.
	unsigned GetPid() const;

	/// This function executes the program using the \p arguments provided. The
	/// invoked program will inherit the stdin, stdout, and stderr file
	/// descriptors, the environment and other configuration settings of the
	/// invoking program. If Path::executable() does not return true when this
	/// function is called then a std::string is thrown.
	/// @returns false in case of error, true otherwise.
	/// @see FindProgramByName
	/// @brief Executes the program with the given set of \p args.
	bool Execute
	( const Path& path, ///< sys::Path object providing the path of the
	///< program to be executed. It is presumed this is the result of
	///< the FindProgramByName method.
	const char** args, ///< A vector of strings that are passed to the
	///< program. The first element should be the name of the program.
	///< The list must be terminated by a null char* entry.
	const char ** env = 0, ///< An optional vector of strings to use for
	///< the program's environment. If not provided, the current program's
	///< environment will be used.
	const sys::Path** redirects = 0, ///< An optional array of pointers to
	///< Paths. If the array is null, no redirection is done. The array
	///< should have a size of at least three. If the pointer in the array
	///< are not null, then the inferior process's stdin(0), stdout(1),
	///< and stderr(2) will be redirected to the corresponding Paths.
	///< When an empty Path is passed in, the corresponding file
	///< descriptor will be disconnected (ie, /dev/null'd) in a portable
	///< way.
	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 = 0 ///< 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.
	);

	/// This function waits for the program to exit. This function will block
	/// the current program until the invoked program exits.
	/// @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
	/// @see Execute
	/// @brief Waits for the program to exit.
	int Wait
	( const Path& path, ///< The path to the child process executable.
	unsigned secondsToWait, ///< 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.
	std::string* ErrMsg ///< 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 waiting.
	);

	/// This function terminates the program.
	/// @returns true if an error occurred.
	/// @see Execute
	/// @brief Terminates the program.
	bool Kill
	( std::string* ErrMsg = 0 ///< 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 killing the
	///< program.
	);

	/// This static constructor (factory) will attempt to locate a program in
	/// the operating system's file system using some pre-determined set of
	/// locations to search (e.g. the PATH on Unix). Paths with slashes are
	/// returned unmodified.
	/// @returns A Path object initialized to the path of the program or a
	/// Path object that is empty (invalid) if the program could not be found.
	/// @brief Construct a Program by finding it by name.
	static Path FindProgramByName(const std::string& name);

	// These methods change the specified standard stream (stdin,
	// stdout, or stderr) to binary mode. They return true if an error
	// occurred
	static bool ChangeStdinToBinary();
	static bool ChangeStdoutToBinary();
	static bool ChangeStderrToBinary();

	/// A convenience function equivalent to Program prg; prg.Execute(..);
	/// prg.Wait(..);
	/// @see Execute, Wait
	static int ExecuteAndWait(const Path& path,
	const char** args,
	const char ** env = 0,
	const sys::Path** redirects = 0,
	unsigned secondsToWait = 0,
	unsigned memoryLimit = 0,
	std::string* ErrMsg = 0);

	/// A convenience function equivalent to Program prg; prg.Execute(..);
	/// @see Execute
	static void ExecuteNoWait(const Path& path,
	const char** args,
	const char ** env = 0,
	const sys::Path** redirects = 0,
	unsigned memoryLimit = 0,
	std::string* ErrMsg = 0);

	/// @}

	};
	}
	}

	#endif