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/Compiler.h" 20 #include "llvm/Support/ErrorOr.h" 21 #include "llvm/Support/FileSystem.h" 22 #include <chrono> 23 #include <optional> 24 #include <system_error> 25 26 namespace llvm { 27 class BitVector; 28 namespace sys { 29 30 /// This is the OS-specific separator for PATH like environment variables: 31 // a colon on Unix or a semicolon on Windows. 32 #if defined(LLVM_ON_UNIX) 33 const char EnvPathSeparator = ':'; 34 #elif defined(_WIN32) 35 const char EnvPathSeparator = ';'; 36 #endif 37 38 #if defined(_WIN32) 39 typedef unsigned long procid_t; // Must match the type of DWORD on Windows. 40 typedef void *process_t; // Must match the type of HANDLE on Windows. 41 #else 42 typedef ::pid_t procid_t; 43 typedef procid_t process_t; 44 #endif 45 46 /// This struct encapsulates information about a process. 47 struct ProcessInfo { 48 enum : procid_t { InvalidPid = 0 }; 49 50 procid_t Pid; /// The process identifier. 51 process_t Process; /// Platform-dependent process object. 52 53 /// The return code, set after execution. 54 int ReturnCode; 55 56 LLVM_ABI ProcessInfo(); 57 }; 58 59 /// This struct encapsulates information about a process execution. 60 struct ProcessStatistics { 61 std::chrono::microseconds TotalTime; 62 std::chrono::microseconds UserTime; 63 uint64_t PeakMemory = 0; ///< Maximum resident set size in KiB. 64 }; 65 66 /// Find the first executable file \p Name in \p Paths. 67 /// 68 /// This does not perform hashing as a shell would but instead stats each PATH 69 /// entry individually so should generally be avoided. Core LLVM library 70 /// functions and options should instead require fully specified paths. 71 /// 72 /// \param Name name of the executable to find. If it contains any system 73 /// slashes, it will be returned as is. 74 /// \param Paths optional list of paths to search for \p Name. If empty it 75 /// will use the system PATH environment instead. 76 /// 77 /// \returns The fully qualified path to the first \p Name in \p Paths if it 78 /// exists. \p Name if \p Name has slashes in it. Otherwise an error. 79 LLVM_ABI ErrorOr<std::string> findProgramByName(StringRef Name, 80 ArrayRef<StringRef> Paths = {}); 81 82 // These functions change the specified standard stream (stdin or stdout) mode 83 // based on the Flags. They return errc::success if the specified stream was 84 // changed. Otherwise, a platform dependent error is returned. 85 LLVM_ABI std::error_code ChangeStdinMode(fs::OpenFlags Flags); 86 LLVM_ABI std::error_code ChangeStdoutMode(fs::OpenFlags Flags); 87 88 // These functions change the specified standard stream (stdin or stdout) to 89 // binary mode. They return errc::success if the specified stream 90 // was changed. Otherwise a platform dependent error is returned. 91 LLVM_ABI std::error_code ChangeStdinToBinary(); 92 LLVM_ABI std::error_code ChangeStdoutToBinary(); 93 94 /// This function executes the program using the arguments provided. The 95 /// invoked program will inherit the stdin, stdout, and stderr file 96 /// descriptors, the environment and other configuration settings of the 97 /// invoking program. 98 /// This function waits for the program to finish, so should be avoided in 99 /// library functions that aren't expected to block. Consider using 100 /// ExecuteNoWait() instead. 101 /// \returns an integer result code indicating the status of the program. 102 /// A zero or positive value indicates the result code of the program. 103 /// -1 indicates failure to execute 104 /// -2 indicates a crash during execution or timeout 105 LLVM_ABI int ExecuteAndWait( 106 StringRef Program, ///< Path of the program to be executed. It is 107 ///< presumed this is the result of the findProgramByName method. 108 ArrayRef<StringRef> Args, ///< An array of strings that are passed to the 109 ///< program. The first element should be the name of the program. 110 ///< The array should **not** be terminated by an empty StringRef. 111 std::optional<ArrayRef<StringRef>> Env = 112 std::nullopt, ///< An optional vector of 113 ///< strings to use for the program's environment. If not provided, the 114 ///< current program's environment will be used. If specified, the 115 ///< vector should **not** be terminated by an empty StringRef. 116 ArrayRef<std::optional<StringRef>> Redirects = {}, ///< 117 ///< An array of optional paths. Should have a size of zero or three. 118 ///< If the array is empty, no redirections are performed. 119 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2) 120 ///< will be redirected to the corresponding paths, if the optional path 121 ///< is present (not \c std::nullopt). 122 ///< When an empty path is passed in, the corresponding file descriptor 123 ///< will be disconnected (ie, /dev/null'd) in a portable way. 124 unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount 125 ///< of time to wait for the child process to exit. If the time 126 ///< expires, the child is killed and this call returns. If zero, 127 ///< this function will wait until the child finishes or forever if 128 ///< it doesn't. 129 unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount 130 ///< of memory can be allocated by process. If memory usage will be 131 ///< higher limit, the child is killed and this call returns. If zero 132 ///< - no memory limit. 133 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 134 ///< string instance in which error messages will be returned. If the 135 ///< string is non-empty upon return an error occurred while invoking the 136 ///< program. 137 bool *ExecutionFailed = nullptr, 138 std::optional<ProcessStatistics> *ProcStat = nullptr, ///< If non-zero, 139 /// provides a pointer to a structure in which process execution 140 /// statistics will be stored. 141 BitVector *AffinityMask = nullptr ///< CPUs or processors the new 142 /// program shall run on. 143 ); 144 145 /// Similar to \ref ExecuteAndWait, but returns immediately. 146 /// \returns The \ref ProcessInfo of the newly launched process. 147 /// \note On Microsoft Windows systems, users will need to either call 148 /// \ref Wait until the process has finished executing or win32's CloseHandle 149 /// API on ProcessInfo.ProcessHandle to avoid memory leaks. 150 LLVM_ABI ProcessInfo ExecuteNoWait( 151 StringRef Program, ArrayRef<StringRef> Args, 152 std::optional<ArrayRef<StringRef>> Env, 153 ArrayRef<std::optional<StringRef>> Redirects = {}, unsigned MemoryLimit = 0, 154 std::string *ErrMsg = nullptr, bool *ExecutionFailed = nullptr, 155 BitVector *AffinityMask = nullptr, 156 /// If true the executed program detatches from the controlling 157 /// terminal. I/O streams such as llvm::outs, llvm::errs, and stdin will 158 /// be closed until redirected to another output location 159 bool DetachProcess = false); 160 161 /// Return true if the given arguments fit within system-specific 162 /// argument length limits. 163 LLVM_ABI bool commandLineFitsWithinSystemLimits(StringRef Program, 164 ArrayRef<StringRef> Args); 165 166 /// Return true if the given arguments fit within system-specific 167 /// argument length limits. 168 LLVM_ABI bool commandLineFitsWithinSystemLimits(StringRef Program, 169 ArrayRef<const char *> Args); 170 171 /// File encoding options when writing contents that a non-UTF8 tool will 172 /// read (on Windows systems). For UNIX, we always use UTF-8. 173 enum WindowsEncodingMethod { 174 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 175 /// encoding conversion". 176 WEM_UTF8, 177 WEM_CurrentCodePage, 178 WEM_UTF16 179 }; 180 181 /// Saves the UTF8-encoded \p contents string into the file \p FileName 182 /// using a specific encoding. 183 /// 184 /// This write file function adds the possibility to choose which encoding 185 /// to use when writing a text file. On Windows, this is important when 186 /// writing files with internationalization support with an encoding that is 187 /// different from the one used in LLVM (UTF-8). We use this when writing 188 /// response files, since GCC tools on MinGW only understand legacy code 189 /// pages, and VisualStudio tools only understand UTF-16. 190 /// For UNIX, using different encodings is silently ignored, since all tools 191 /// work well with UTF-8. 192 /// This function assumes that you only use UTF-8 *text* data and will convert 193 /// it to your desired encoding before writing to the file. 194 /// 195 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 196 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 197 /// our best shot to make gcc/ld understand international characters. This 198 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 199 /// 200 /// \returns non-zero error_code if failed 201 LLVM_ABI std::error_code 202 writeFileWithEncoding(StringRef FileName, StringRef Contents, 203 WindowsEncodingMethod Encoding = WEM_UTF8); 204 205 /// This function waits for the process specified by \p PI to finish. 206 /// \returns A \see ProcessInfo struct with Pid set to: 207 /// \li The process id of the child process if the child process has changed 208 /// state. 209 /// \li 0 if the child process has not changed state. 210 /// \note Users of this function should always check the ReturnCode member of 211 /// the \see ProcessInfo returned from this function. 212 LLVM_ABI ProcessInfo Wait( 213 const ProcessInfo &PI, ///< The child process that should be waited on. 214 std::optional<unsigned> SecondsToWait, ///< If std::nullopt, waits until 215 ///< child has terminated. 216 ///< If a value, this specifies the amount of time to wait for the child 217 ///< process. If the time expires, and \p Polling is false, the child is 218 ///< killed and this < function returns. If the time expires and \p 219 ///< Polling is true, the child is resumed. 220 ///< 221 ///< If zero, this function will perform a non-blocking 222 ///< wait on the child process. 223 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 224 ///< string instance in which error messages will be returned. If the 225 ///< string is non-empty upon return an error occurred while invoking the 226 ///< program. 227 std::optional<ProcessStatistics> *ProcStat = 228 nullptr, ///< If non-zero, provides 229 /// a pointer to a structure in which process execution statistics will 230 /// be stored. 231 232 bool Polling = false ///< If true, do not kill the process on timeout. 233 ); 234 235 /// Print a command argument, and optionally quote it. 236 LLVM_ABI void printArg(llvm::raw_ostream &OS, StringRef Arg, bool Quote); 237 238 #if defined(_WIN32) 239 /// Given a list of command line arguments, quote and escape them as necessary 240 /// to build a single flat command line appropriate for calling CreateProcess 241 /// on 242 /// Windows. 243 LLVM_ABI ErrorOr<std::wstring> 244 flattenWindowsCommandLine(ArrayRef<StringRef> Args); 245 #endif 246 } // namespace sys 247 } // namespace llvm 248 249 #endif 250