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/BitVector.h" 18 #include "llvm/ADT/Optional.h" 19 #include "llvm/ADT/StringRef.h" 20 #include "llvm/Config/llvm-config.h" 21 #include "llvm/Support/ErrorOr.h" 22 #include "llvm/Support/FileSystem.h" 23 #include <chrono> 24 #include <system_error> 25 26 namespace llvm { 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 Optional<ArrayRef<StringRef>> Env = None, ///< An optional vector of 111 ///< strings to use for the program's environment. If not provided, the 112 ///< current program's environment will be used. If specified, the 113 ///< vector should **not** be terminated by an empty StringRef. 114 ArrayRef<Optional<StringRef>> Redirects = {}, ///< 115 ///< An array of optional paths. Should have a size of zero or three. 116 ///< If the array is empty, no redirections are performed. 117 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2) 118 ///< will be redirected to the corresponding paths, if the optional path 119 ///< is present (not \c llvm::None). 120 ///< When an empty path is passed in, the corresponding file descriptor 121 ///< will be disconnected (ie, /dev/null'd) in a portable way. 122 unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount 123 ///< of time to wait for the child process to exit. If the time 124 ///< expires, the child is killed and this call returns. If zero, 125 ///< this function will wait until the child finishes or forever if 126 ///< it doesn't. 127 unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount 128 ///< of memory can be allocated by process. If memory usage will be 129 ///< higher limit, the child is killed and this call returns. If zero 130 ///< - no memory limit. 131 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 132 ///< string instance in which error messages will be returned. If the 133 ///< string is non-empty upon return an error occurred while invoking the 134 ///< program. 135 bool *ExecutionFailed = nullptr, 136 Optional<ProcessStatistics> *ProcStat = nullptr, ///< If non-zero, 137 /// provides a pointer to a structure in which process execution 138 /// statistics will be stored. 139 BitVector *AffinityMask = nullptr ///< CPUs or processors the new 140 /// program shall run on. 141 ); 142 143 /// Similar to ExecuteAndWait, but returns immediately. 144 /// @returns The \see ProcessInfo of the newly launched process. 145 /// \note On Microsoft Windows systems, users will need to either call 146 /// \see Wait until the process finished execution or win32 CloseHandle() API 147 /// on ProcessInfo.ProcessHandle to avoid memory leaks. 148 ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef<StringRef> Args, 149 Optional<ArrayRef<StringRef>> Env, 150 ArrayRef<Optional<StringRef>> Redirects = {}, 151 unsigned MemoryLimit = 0, 152 std::string *ErrMsg = nullptr, 153 bool *ExecutionFailed = nullptr, 154 BitVector *AffinityMask = nullptr); 155 156 /// Return true if the given arguments fit within system-specific 157 /// argument length limits. 158 bool commandLineFitsWithinSystemLimits(StringRef Program, 159 ArrayRef<StringRef> Args); 160 161 /// Return true if the given arguments fit within system-specific 162 /// argument length limits. 163 bool commandLineFitsWithinSystemLimits(StringRef Program, 164 ArrayRef<const char *> Args); 165 166 /// File encoding options when writing contents that a non-UTF8 tool will 167 /// read (on Windows systems). For UNIX, we always use UTF-8. 168 enum WindowsEncodingMethod { 169 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 170 /// encoding conversion". 171 WEM_UTF8, 172 WEM_CurrentCodePage, 173 WEM_UTF16 174 }; 175 176 /// Saves the UTF8-encoded \p contents string into the file \p FileName 177 /// using a specific encoding. 178 /// 179 /// This write file function adds the possibility to choose which encoding 180 /// to use when writing a text file. On Windows, this is important when 181 /// writing files with internationalization support with an encoding that is 182 /// different from the one used in LLVM (UTF-8). We use this when writing 183 /// response files, since GCC tools on MinGW only understand legacy code 184 /// pages, and VisualStudio tools only understand UTF-16. 185 /// For UNIX, using different encodings is silently ignored, since all tools 186 /// work well with UTF-8. 187 /// This function assumes that you only use UTF-8 *text* data and will convert 188 /// it to your desired encoding before writing to the file. 189 /// 190 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 191 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 192 /// our best shot to make gcc/ld understand international characters. This 193 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 194 /// 195 /// \returns non-zero error_code if failed 196 std::error_code 197 writeFileWithEncoding(StringRef FileName, StringRef Contents, 198 WindowsEncodingMethod Encoding = WEM_UTF8); 199 200 /// This function waits for the process specified by \p PI to finish. 201 /// \returns A \see ProcessInfo struct with Pid set to: 202 /// \li The process id of the child process if the child process has changed 203 /// state. 204 /// \li 0 if the child process has not changed state. 205 /// \note Users of this function should always check the ReturnCode member of 206 /// the \see ProcessInfo returned from this function. 207 ProcessInfo Wait( 208 const ProcessInfo &PI, ///< The child process that should be waited on. 209 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 210 ///< time to wait for the child process to exit. If the time expires, the 211 ///< child is killed and this function returns. If zero, this function 212 ///< will perform a non-blocking wait on the child process. 213 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 214 ///< until child has terminated. 215 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 216 ///< string instance in which error messages will be returned. If the 217 ///< string is non-empty upon return an error occurred while invoking the 218 ///< program. 219 Optional<ProcessStatistics> *ProcStat = nullptr ///< If non-zero, provides 220 /// a pointer to a structure in which process execution statistics will be 221 /// stored. 222 ); 223 224 /// Print a command argument, and optionally quote it. 225 void printArg(llvm::raw_ostream &OS, StringRef Arg, bool Quote); 226 227 #if defined(_WIN32) 228 /// Given a list of command line arguments, quote and escape them as necessary 229 /// to build a single flat command line appropriate for calling CreateProcess 230 /// on 231 /// Windows. 232 ErrorOr<std::wstring> flattenWindowsCommandLine(ArrayRef<StringRef> Args); 233 #endif 234 } 235 } 236 237 #endif 238