1 //===- llvm/Support/Program.h ------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file declares the llvm::sys::Program class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_SUPPORT_PROGRAM_H 14 #define LLVM_SUPPORT_PROGRAM_H 15 16 #include "llvm/ADT/ArrayRef.h" 17 #include "llvm/ADT/StringRef.h" 18 #include "llvm/Config/llvm-config.h" 19 #include "llvm/Support/ErrorOr.h" 20 #include "llvm/Support/FileSystem.h" 21 #include <chrono> 22 #include <optional> 23 #include <system_error> 24 25 namespace llvm { 26 class BitVector; 27 namespace sys { 28 29 /// This is the OS-specific separator for PATH like environment variables: 30 // a colon on Unix or a semicolon on Windows. 31 #if defined(LLVM_ON_UNIX) 32 const char EnvPathSeparator = ':'; 33 #elif defined (_WIN32) 34 const char EnvPathSeparator = ';'; 35 #endif 36 37 #if defined(_WIN32) 38 typedef unsigned long procid_t; // Must match the type of DWORD on Windows. 39 typedef void *process_t; // Must match the type of HANDLE on Windows. 40 #else 41 typedef ::pid_t procid_t; 42 typedef procid_t process_t; 43 #endif 44 45 /// This struct encapsulates information about a process. 46 struct ProcessInfo { 47 enum : procid_t { InvalidPid = 0 }; 48 49 procid_t Pid; /// The process identifier. 50 process_t Process; /// Platform-dependent process object. 51 52 /// The return code, set after execution. 53 int ReturnCode; 54 55 ProcessInfo(); 56 }; 57 58 /// This struct encapsulates information about a process execution. 59 struct ProcessStatistics { 60 std::chrono::microseconds TotalTime; 61 std::chrono::microseconds UserTime; 62 uint64_t PeakMemory = 0; ///< Maximum resident set size in KiB. 63 }; 64 65 /// Find the first executable file \p Name in \p Paths. 66 /// 67 /// This does not perform hashing as a shell would but instead stats each PATH 68 /// entry individually so should generally be avoided. Core LLVM library 69 /// functions and options should instead require fully specified paths. 70 /// 71 /// \param Name name of the executable to find. If it contains any system 72 /// slashes, it will be returned as is. 73 /// \param Paths optional list of paths to search for \p Name. If empty it 74 /// will use the system PATH environment instead. 75 /// 76 /// \returns The fully qualified path to the first \p Name in \p Paths if it 77 /// exists. \p Name if \p Name has slashes in it. Otherwise an error. 78 ErrorOr<std::string> 79 findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {}); 80 81 // These functions change the specified standard stream (stdin or stdout) mode 82 // based on the Flags. They return errc::success if the specified stream was 83 // changed. Otherwise, a platform dependent error is returned. 84 std::error_code ChangeStdinMode(fs::OpenFlags Flags); 85 std::error_code ChangeStdoutMode(fs::OpenFlags Flags); 86 87 // These functions change the specified standard stream (stdin or stdout) to 88 // binary mode. They return errc::success if the specified stream 89 // was changed. Otherwise a platform dependent error is returned. 90 std::error_code ChangeStdinToBinary(); 91 std::error_code ChangeStdoutToBinary(); 92 93 /// This function executes the program using the arguments provided. The 94 /// invoked program will inherit the stdin, stdout, and stderr file 95 /// descriptors, the environment and other configuration settings of the 96 /// invoking program. 97 /// This function waits for the program to finish, so should be avoided in 98 /// library functions that aren't expected to block. Consider using 99 /// ExecuteNoWait() instead. 100 /// \returns an integer result code indicating the status of the program. 101 /// A zero or positive value indicates the result code of the program. 102 /// -1 indicates failure to execute 103 /// -2 indicates a crash during execution or timeout 104 int ExecuteAndWait( 105 StringRef Program, ///< Path of the program to be executed. It is 106 ///< presumed this is the result of the findProgramByName method. 107 ArrayRef<StringRef> Args, ///< An array of strings that are passed to the 108 ///< program. The first element should be the name of the program. 109 ///< The array should **not** be terminated by an empty StringRef. 110 std::optional<ArrayRef<StringRef>> Env = 111 std::nullopt, ///< An optional vector of 112 ///< strings to use for the program's environment. If not provided, the 113 ///< current program's environment will be used. If specified, the 114 ///< vector should **not** be terminated by an empty StringRef. 115 ArrayRef<std::optional<StringRef>> Redirects = {}, ///< 116 ///< An array of optional paths. Should have a size of zero or three. 117 ///< If the array is empty, no redirections are performed. 118 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2) 119 ///< will be redirected to the corresponding paths, if the optional path 120 ///< is present (not \c std::nullopt). 121 ///< When an empty path is passed in, the corresponding file descriptor 122 ///< will be disconnected (ie, /dev/null'd) in a portable way. 123 unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount 124 ///< of time to wait for the child process to exit. If the time 125 ///< expires, the child is killed and this call returns. If zero, 126 ///< this function will wait until the child finishes or forever if 127 ///< it doesn't. 128 unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount 129 ///< of memory can be allocated by process. If memory usage will be 130 ///< higher limit, the child is killed and this call returns. If zero 131 ///< - no memory limit. 132 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 133 ///< string instance in which error messages will be returned. If the 134 ///< string is non-empty upon return an error occurred while invoking the 135 ///< program. 136 bool *ExecutionFailed = nullptr, 137 std::optional<ProcessStatistics> *ProcStat = nullptr, ///< If non-zero, 138 /// provides a pointer to a structure in which process execution 139 /// statistics will be stored. 140 BitVector *AffinityMask = nullptr ///< CPUs or processors the new 141 /// program shall run on. 142 ); 143 144 /// Similar to ExecuteAndWait, but returns immediately. 145 /// @returns The \see ProcessInfo of the newly launched process. 146 /// \note On Microsoft Windows systems, users will need to either call 147 /// \see Wait until the process finished execution or win32 CloseHandle() API 148 /// on ProcessInfo.ProcessHandle to avoid memory leaks. 149 ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef<StringRef> Args, 150 std::optional<ArrayRef<StringRef>> Env, 151 ArrayRef<std::optional<StringRef>> Redirects = {}, 152 unsigned MemoryLimit = 0, 153 std::string *ErrMsg = nullptr, 154 bool *ExecutionFailed = nullptr, 155 BitVector *AffinityMask = nullptr); 156 157 /// Return true if the given arguments fit within system-specific 158 /// argument length limits. 159 bool commandLineFitsWithinSystemLimits(StringRef Program, 160 ArrayRef<StringRef> Args); 161 162 /// Return true if the given arguments fit within system-specific 163 /// argument length limits. 164 bool commandLineFitsWithinSystemLimits(StringRef Program, 165 ArrayRef<const char *> Args); 166 167 /// File encoding options when writing contents that a non-UTF8 tool will 168 /// read (on Windows systems). For UNIX, we always use UTF-8. 169 enum WindowsEncodingMethod { 170 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 171 /// encoding conversion". 172 WEM_UTF8, 173 WEM_CurrentCodePage, 174 WEM_UTF16 175 }; 176 177 /// Saves the UTF8-encoded \p contents string into the file \p FileName 178 /// using a specific encoding. 179 /// 180 /// This write file function adds the possibility to choose which encoding 181 /// to use when writing a text file. On Windows, this is important when 182 /// writing files with internationalization support with an encoding that is 183 /// different from the one used in LLVM (UTF-8). We use this when writing 184 /// response files, since GCC tools on MinGW only understand legacy code 185 /// pages, and VisualStudio tools only understand UTF-16. 186 /// For UNIX, using different encodings is silently ignored, since all tools 187 /// work well with UTF-8. 188 /// This function assumes that you only use UTF-8 *text* data and will convert 189 /// it to your desired encoding before writing to the file. 190 /// 191 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 192 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 193 /// our best shot to make gcc/ld understand international characters. This 194 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 195 /// 196 /// \returns non-zero error_code if failed 197 std::error_code 198 writeFileWithEncoding(StringRef FileName, StringRef Contents, 199 WindowsEncodingMethod Encoding = WEM_UTF8); 200 201 /// This function waits for the process specified by \p PI to finish. 202 /// \returns A \see ProcessInfo struct with Pid set to: 203 /// \li The process id of the child process if the child process has changed 204 /// state. 205 /// \li 0 if the child process has not changed state. 206 /// \note Users of this function should always check the ReturnCode member of 207 /// the \see ProcessInfo returned from this function. 208 ProcessInfo 209 Wait(const ProcessInfo &PI, ///< The child process that should be waited on. 210 std::optional<unsigned> SecondsToWait, ///< If std::nullopt, waits until 211 ///< child has terminated. 212 ///< If a value, this specifies the amount of time to wait for the child 213 ///< process. If the time expires, and \p Polling is false, the child is 214 ///< killed and this < function returns. If the time expires and \p 215 ///< Polling is true, the child is resumed. 216 ///< 217 ///< If zero, this function will perform a non-blocking 218 ///< wait on the child process. 219 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 220 ///< string instance in which error messages will be returned. If the 221 ///< string is non-empty upon return an error occurred while invoking the 222 ///< program. 223 std::optional<ProcessStatistics> *ProcStat = 224 nullptr, ///< If non-zero, provides 225 /// a pointer to a structure in which process execution statistics will 226 /// be stored. 227 228 bool Polling = false ///< If true, do not kill the process on timeout. 229 ); 230 231 /// Print a command argument, and optionally quote it. 232 void printArg(llvm::raw_ostream &OS, StringRef Arg, bool Quote); 233 234 #if defined(_WIN32) 235 /// Given a list of command line arguments, quote and escape them as necessary 236 /// to build a single flat command line appropriate for calling CreateProcess 237 /// on 238 /// Windows. 239 ErrorOr<std::wstring> flattenWindowsCommandLine(ArrayRef<StringRef> Args); 240 #endif 241 } 242 } 243 244 #endif 245