//===- llvm/Support/Process.h -----------------------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// /// \file /// /// Provides a library for accessing information about this process and other /// processes on the operating system. Also provides means of spawning /// subprocess for commands. The design of this library is modeled after the /// proposed design of the Boost.Process library, and is design specifically to /// follow the style of standard libraries and potentially become a proposal /// for a standard library. /// /// This file declares the llvm::sys::Process class which contains a collection /// of legacy static interfaces for extracting various information about the /// current process. The goal is to migrate users of this API over to the new /// interfaces. /// //===----------------------------------------------------------------------===// #ifndef LLVM_SUPPORT_PROCESS_H #define LLVM_SUPPORT_PROCESS_H #include "llvm/ADT/ArrayRef.h" #include "llvm/ADT/Optional.h" #include "llvm/Config/llvm-config.h" #include "llvm/Support/Allocator.h" #include "llvm/Support/DataTypes.h" #include "llvm/Support/TimeValue.h" #include <system_error> namespace llvm { class StringRef; namespace sys { /// \brief A collection of legacy interfaces for querying information about the /// current executing process. class Process { public: static unsigned getPageSize(); /// \brief Return process memory usage. /// This static function will return the total amount of memory allocated /// by the process. This only counts the memory allocated via the malloc, /// calloc and realloc functions and includes any "free" holes in the /// allocated space. static size_t GetMallocUsage(); /// This static function will set \p user_time to the amount of CPU time /// spent in user (non-kernel) mode and \p sys_time to the amount of CPU /// time spent in system (kernel) mode. If the operating system does not /// support collection of these metrics, a zero TimeValue will be for both /// values. /// \param elapsed Returns the TimeValue::now() giving current time /// \param user_time Returns the current amount of user time for the process /// \param sys_time Returns the current amount of system time for the process static void GetTimeUsage(TimeValue &elapsed, TimeValue &user_time, TimeValue &sys_time); /// This function makes the necessary calls to the operating system to /// prevent core files or any other kind of large memory dumps that can /// occur when a program fails. /// @brief Prevent core file generation. static void PreventCoreFiles(); // This function returns the environment variable \arg name's value as a UTF-8 // string. \arg Name is assumed to be in UTF-8 encoding too. static Optional<std::string> GetEnv(StringRef name); /// This function searches for an existing file in the list of directories /// in a PATH like environment variable, and returns the first file found, /// according to the order of the entries in the PATH like environment /// variable. static Optional<std::string> FindInEnvPath(const std::string& EnvName, const std::string& FileName); /// This function returns a SmallVector containing the arguments passed from /// the operating system to the program. This function expects to be handed /// the vector passed in from main. static std::error_code GetArgumentVector(SmallVectorImpl<const char *> &Args, ArrayRef<const char *> ArgsFromMain, SpecificBumpPtrAllocator<char> &ArgAllocator); // This functions ensures that the standard file descriptors (input, output, // and error) are properly mapped to a file descriptor before we use any of // them. This should only be called by standalone programs, library // components should not call this. static std::error_code FixupStandardFileDescriptors(); // This function safely closes a file descriptor. It is not safe to retry // close(2) when it returns with errno equivalent to EINTR; this is because // *nixen cannot agree if the file descriptor is, in fact, closed when this // occurs. // // N.B. Some operating systems, due to thread cancellation, cannot properly // guarantee that it will or will not be closed one way or the other! static std::error_code SafelyCloseFileDescriptor(int FD); /// This function determines if the standard input is connected directly /// to a user's input (keyboard probably), rather than coming from a file /// or pipe. static bool StandardInIsUserInput(); /// This function determines if the standard output is connected to a /// "tty" or "console" window. That is, the output would be displayed to /// the user rather than being put on a pipe or stored in a file. static bool StandardOutIsDisplayed(); /// This function determines if the standard error is connected to a /// "tty" or "console" window. That is, the output would be displayed to /// the user rather than being put on a pipe or stored in a file. static bool StandardErrIsDisplayed(); /// This function determines if the given file descriptor is connected to /// a "tty" or "console" window. That is, the output would be displayed to /// the user rather than being put on a pipe or stored in a file. static bool FileDescriptorIsDisplayed(int fd); /// This function determines if the given file descriptor is displayd and /// supports colors. static bool FileDescriptorHasColors(int fd); /// This function determines the number of columns in the window /// if standard output is connected to a "tty" or "console" /// window. If standard output is not connected to a tty or /// console, or if the number of columns cannot be determined, /// this routine returns zero. static unsigned StandardOutColumns(); /// This function determines the number of columns in the window /// if standard error is connected to a "tty" or "console" /// window. If standard error is not connected to a tty or /// console, or if the number of columns cannot be determined, /// this routine returns zero. static unsigned StandardErrColumns(); /// This function determines whether the terminal connected to standard /// output supports colors. If standard output is not connected to a /// terminal, this function returns false. static bool StandardOutHasColors(); /// This function determines whether the terminal connected to standard /// error supports colors. If standard error is not connected to a /// terminal, this function returns false. static bool StandardErrHasColors(); /// Enables or disables whether ANSI escape sequences are used to output /// colors. This only has an effect on Windows. /// Note: Setting this option is not thread-safe and should only be done /// during initialization. static void UseANSIEscapeCodes(bool enable); /// Whether changing colors requires the output to be flushed. /// This is needed on systems that don't support escape sequences for /// changing colors. static bool ColorNeedsFlush(); /// This function returns the colorcode escape sequences. /// If ColorNeedsFlush() is true then this function will change the colors /// and return an empty escape sequence. In that case it is the /// responsibility of the client to flush the output stream prior to /// calling this function. static const char *OutputColor(char c, bool bold, bool bg); /// Same as OutputColor, but only enables the bold attribute. static const char *OutputBold(bool bg); /// This function returns the escape sequence to reverse forground and /// background colors. static const char *OutputReverse(); /// Resets the terminals colors, or returns an escape sequence to do so. static const char *ResetColor(); /// Get the result of a process wide random number generator. The /// generator will be automatically seeded in non-deterministic fashion. static unsigned GetRandomNumber(); }; } } #endif