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/Optional.h" 18 #include "llvm/ADT/StringRef.h" 19 #include "llvm/Config/llvm-config.h" 20 #include "llvm/Support/ErrorOr.h" 21 #include <system_error> 22 23 namespace llvm { 24 namespace sys { 25 26 /// This is the OS-specific separator for PATH like environment variables: 27 // a colon on Unix or a semicolon on Windows. 28 #if defined(LLVM_ON_UNIX) 29 const char EnvPathSeparator = ':'; 30 #elif defined (_WIN32) 31 const char EnvPathSeparator = ';'; 32 #endif 33 34 #if defined(_WIN32) 35 typedef unsigned long procid_t; // Must match the type of DWORD on Windows. 36 typedef void *process_t; // Must match the type of HANDLE on Windows. 37 #else 38 typedef pid_t procid_t; 39 typedef procid_t process_t; 40 #endif 41 42 /// This struct encapsulates information about a process. 43 struct ProcessInfo { 44 enum : procid_t { InvalidPid = 0 }; 45 46 procid_t Pid; /// The process identifier. 47 process_t Process; /// Platform-dependent process object. 48 49 /// The return code, set after execution. 50 int ReturnCode; 51 52 ProcessInfo(); 53 }; 54 55 /// Find the first executable file \p Name in \p Paths. 56 /// 57 /// This does not perform hashing as a shell would but instead stats each PATH 58 /// entry individually so should generally be avoided. Core LLVM library 59 /// functions and options should instead require fully specified paths. 60 /// 61 /// \param Name name of the executable to find. If it contains any system 62 /// slashes, it will be returned as is. 63 /// \param Paths optional list of paths to search for \p Name. If empty it 64 /// will use the system PATH environment instead. 65 /// 66 /// \returns The fully qualified path to the first \p Name in \p Paths if it 67 /// exists. \p Name if \p Name has slashes in it. Otherwise an error. 68 ErrorOr<std::string> 69 findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {}); 70 71 // These functions change the specified standard stream (stdin or stdout) to 72 // binary mode. They return errc::success if the specified stream 73 // was changed. Otherwise a platform dependent error is returned. 74 std::error_code ChangeStdinToBinary(); 75 std::error_code ChangeStdoutToBinary(); 76 77 /// This function executes the program using the arguments provided. The 78 /// invoked program will inherit the stdin, stdout, and stderr file 79 /// descriptors, the environment and other configuration settings of the 80 /// invoking program. 81 /// This function waits for the program to finish, so should be avoided in 82 /// library functions that aren't expected to block. Consider using 83 /// ExecuteNoWait() instead. 84 /// \returns an integer result code indicating the status of the program. 85 /// A zero or positive value indicates the result code of the program. 86 /// -1 indicates failure to execute 87 /// -2 indicates a crash during execution or timeout 88 int ExecuteAndWait( 89 StringRef Program, ///< Path of the program to be executed. It is 90 ///< presumed this is the result of the findProgramByName method. 91 ArrayRef<StringRef> Args, ///< An array of strings that are passed to the 92 ///< program. The first element should be the name of the program. 93 ///< The array should **not** be terminated by an empty StringRef. 94 Optional<ArrayRef<StringRef>> Env = None, ///< An optional vector of 95 ///< strings to use for the program's environment. If not provided, the 96 ///< current program's environment will be used. If specified, the 97 ///< vector should **not** be terminated by an empty StringRef. 98 ArrayRef<Optional<StringRef>> Redirects = {}, ///< 99 ///< An array of optional paths. Should have a size of zero or three. 100 ///< If the array is empty, no redirections are performed. 101 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2) 102 ///< will be redirected to the corresponding paths, if the optional path 103 ///< is present (not \c llvm::None). 104 ///< When an empty path is passed in, the corresponding file descriptor 105 ///< will be disconnected (ie, /dev/null'd) in a portable way. 106 unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount 107 ///< of time to wait for the child process to exit. If the time 108 ///< expires, the child is killed and this call returns. If zero, 109 ///< this function will wait until the child finishes or forever if 110 ///< it doesn't. 111 unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount 112 ///< of memory can be allocated by process. If memory usage will be 113 ///< higher limit, the child is killed and this call returns. If zero 114 ///< - no memory limit. 115 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 116 ///< string instance in which error messages will be returned. If the 117 ///< string is non-empty upon return an error occurred while invoking the 118 ///< program. 119 bool *ExecutionFailed = nullptr); 120 121 /// Similar to ExecuteAndWait, but returns immediately. 122 /// @returns The \see ProcessInfo of the newly launced process. 123 /// \note On Microsoft Windows systems, users will need to either call 124 /// \see Wait until the process finished execution or win32 CloseHandle() API 125 /// on ProcessInfo.ProcessHandle to avoid memory leaks. 126 ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef<StringRef> Args, 127 Optional<ArrayRef<StringRef>> Env, 128 ArrayRef<Optional<StringRef>> Redirects = {}, 129 unsigned MemoryLimit = 0, 130 std::string *ErrMsg = nullptr, 131 bool *ExecutionFailed = nullptr); 132 133 /// Return true if the given arguments fit within system-specific 134 /// argument length limits. 135 bool commandLineFitsWithinSystemLimits(StringRef Program, 136 ArrayRef<StringRef> Args); 137 138 /// Return true if the given arguments fit within system-specific 139 /// argument length limits. 140 bool commandLineFitsWithinSystemLimits(StringRef Program, 141 ArrayRef<const char *> Args); 142 143 /// File encoding options when writing contents that a non-UTF8 tool will 144 /// read (on Windows systems). For UNIX, we always use UTF-8. 145 enum WindowsEncodingMethod { 146 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 147 /// encoding conversion". 148 WEM_UTF8, 149 WEM_CurrentCodePage, 150 WEM_UTF16 151 }; 152 153 /// Saves the UTF8-encoded \p contents string into the file \p FileName 154 /// using a specific encoding. 155 /// 156 /// This write file function adds the possibility to choose which encoding 157 /// to use when writing a text file. On Windows, this is important when 158 /// writing files with internationalization support with an encoding that is 159 /// different from the one used in LLVM (UTF-8). We use this when writing 160 /// response files, since GCC tools on MinGW only understand legacy code 161 /// pages, and VisualStudio tools only understand UTF-16. 162 /// For UNIX, using different encodings is silently ignored, since all tools 163 /// work well with UTF-8. 164 /// This function assumes that you only use UTF-8 *text* data and will convert 165 /// it to your desired encoding before writing to the file. 166 /// 167 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 168 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 169 /// our best shot to make gcc/ld understand international characters. This 170 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 171 /// 172 /// \returns non-zero error_code if failed 173 std::error_code 174 writeFileWithEncoding(StringRef FileName, StringRef Contents, 175 WindowsEncodingMethod Encoding = WEM_UTF8); 176 177 /// This function waits for the process specified by \p PI to finish. 178 /// \returns A \see ProcessInfo struct with Pid set to: 179 /// \li The process id of the child process if the child process has changed 180 /// state. 181 /// \li 0 if the child process has not changed state. 182 /// \note Users of this function should always check the ReturnCode member of 183 /// the \see ProcessInfo returned from this function. 184 ProcessInfo Wait( 185 const ProcessInfo &PI, ///< The child process that should be waited on. 186 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 187 ///< time to wait for the child process to exit. If the time expires, the 188 ///< child is killed and this function returns. If zero, this function 189 ///< will perform a non-blocking wait on the child process. 190 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 191 ///< until child has terminated. 192 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a 193 ///< string instance in which error messages will be returned. If the 194 ///< string is non-empty upon return an error occurred while invoking the 195 ///< program. 196 ); 197 198 #if defined(_WIN32) 199 /// Given a list of command line arguments, quote and escape them as necessary 200 /// to build a single flat command line appropriate for calling CreateProcess 201 /// on 202 /// Windows. 203 std::string flattenWindowsCommandLine(ArrayRef<StringRef> Args); 204 #endif 205 } 206 } 207 208 #endif 209