1 //===- llvm/Support/Program.h ------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file declares the llvm::sys::Program class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_SUPPORT_PROGRAM_H 15 #define LLVM_SUPPORT_PROGRAM_H 16 17 #include "llvm/ADT/ArrayRef.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 <system_error> 23 24 namespace llvm { 25 namespace sys { 26 27 /// This is the OS-specific separator for PATH like environment variables: 28 // a colon on Unix or a semicolon on Windows. 29 #if defined(LLVM_ON_UNIX) 30 const char EnvPathSeparator = ':'; 31 #elif defined (_WIN32) 32 const char EnvPathSeparator = ';'; 33 #endif 34 35 #if defined(_WIN32) 36 typedef unsigned long procid_t; // Must match the type of DWORD on Windows. 37 typedef void *process_t; // Must match the type of HANDLE on Windows. 38 #else 39 typedef pid_t procid_t; 40 typedef procid_t process_t; 41 #endif 42 43 /// This struct encapsulates information about a process. 44 struct ProcessInfo { 45 enum : procid_t { InvalidPid = 0 }; 46 47 procid_t Pid; /// The process identifier. 48 process_t Process; /// Platform-dependent process object. 49 50 /// The return code, set after execution. 51 int ReturnCode; 52 53 ProcessInfo(); 54 }; 55 56 /// Find the first executable file \p Name in \p Paths. 57 /// 58 /// This does not perform hashing as a shell would but instead stats each PATH 59 /// entry individually so should generally be avoided. Core LLVM library 60 /// functions and options should instead require fully specified paths. 61 /// 62 /// \param Name name of the executable to find. If it contains any system 63 /// slashes, it will be returned as is. 64 /// \param Paths optional list of paths to search for \p Name. If empty it 65 /// will use the system PATH environment instead. 66 /// 67 /// \returns The fully qualified path to the first \p Name in \p Paths if it 68 /// exists. \p Name if \p Name has slashes in it. Otherwise an error. 69 ErrorOr<std::string> 70 findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {}); 71 72 // These functions change the specified standard stream (stdin or stdout) to 73 // binary mode. They return errc::success if the specified stream 74 // was changed. Otherwise a platform dependent error is returned. 75 std::error_code ChangeStdinToBinary(); 76 std::error_code ChangeStdoutToBinary(); 77 78 /// This function executes the program using the arguments provided. The 79 /// invoked program will inherit the stdin, stdout, and stderr file 80 /// descriptors, the environment and other configuration settings of the 81 /// invoking program. 82 /// This function waits for the program to finish, so should be avoided in 83 /// library functions that aren't expected to block. Consider using 84 /// ExecuteNoWait() instead. 85 /// \returns an integer result code indicating the status of the program. 86 /// A zero or positive value indicates the result code of the program. 87 /// -1 indicates failure to execute 88 /// -2 indicates a crash during execution or timeout 89 int ExecuteAndWait( 90 StringRef Program, ///< Path of the program to be executed. It is 91 ///< presumed this is the result of the findProgramByName method. 92 ArrayRef<StringRef> Args, ///< An array of strings that are passed to the 93 ///< program. The first element should be the name of the program. 94 ///< The array should **not** be terminated by an empty StringRef. 95 Optional<ArrayRef<StringRef>> Env = None, ///< An optional vector of 96 ///< strings to use for the program's environment. If not provided, the 97 ///< current program's environment will be used. If specified, the 98 ///< vector should **not** be terminated by an empty StringRef. 99 ArrayRef<Optional<StringRef>> Redirects = {}, ///< 100 ///< An array of optional paths. Should have a size of zero or three. 101 ///< If the array is empty, no redirections are performed. 102 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2) 103 ///< will be redirected to the corresponding paths, if the optional path 104 ///< is present (not \c llvm::None). 105 ///< When an empty path is passed in, the corresponding file descriptor 106 ///< will be disconnected (ie, /dev/null'd) in a portable way. 107 unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount 108 ///< of time to wait for the child process to exit. If the time 109 ///< expires, the child is killed and this call returns. If zero, 110 ///< this function will wait until the child finishes or forever if 111 ///< it doesn't. 112 unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount 113 ///< of memory can be allocated by process. If memory usage will be 114 ///< higher limit, the child is killed and this call returns. If zero 115 ///< - no memory limit. 116 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 117 ///< string instance in which error messages will be returned. If the 118 ///< string is non-empty upon return an error occurred while invoking the 119 ///< program. 120 bool *ExecutionFailed = nullptr); 121 122 /// Similar to ExecuteAndWait, but returns immediately. 123 /// @returns The \see ProcessInfo of the newly launced process. 124 /// \note On Microsoft Windows systems, users will need to either call 125 /// \see Wait until the process finished execution or win32 CloseHandle() API 126 /// on ProcessInfo.ProcessHandle to avoid memory leaks. 127 ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef<StringRef> Args, 128 Optional<ArrayRef<StringRef>> Env, 129 ArrayRef<Optional<StringRef>> Redirects = {}, 130 unsigned MemoryLimit = 0, 131 std::string *ErrMsg = nullptr, 132 bool *ExecutionFailed = nullptr); 133 134 /// Return true if the given arguments fit within system-specific 135 /// argument length limits. 136 bool commandLineFitsWithinSystemLimits(StringRef Program, 137 ArrayRef<StringRef> Args); 138 139 /// Return true if the given arguments fit within system-specific 140 /// argument length limits. 141 bool commandLineFitsWithinSystemLimits(StringRef Program, 142 ArrayRef<const char *> Args); 143 144 /// File encoding options when writing contents that a non-UTF8 tool will 145 /// read (on Windows systems). For UNIX, we always use UTF-8. 146 enum WindowsEncodingMethod { 147 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 148 /// encoding conversion". 149 WEM_UTF8, 150 WEM_CurrentCodePage, 151 WEM_UTF16 152 }; 153 154 /// Saves the UTF8-encoded \p contents string into the file \p FileName 155 /// using a specific encoding. 156 /// 157 /// This write file function adds the possibility to choose which encoding 158 /// to use when writing a text file. On Windows, this is important when 159 /// writing files with internationalization support with an encoding that is 160 /// different from the one used in LLVM (UTF-8). We use this when writing 161 /// response files, since GCC tools on MinGW only understand legacy code 162 /// pages, and VisualStudio tools only understand UTF-16. 163 /// For UNIX, using different encodings is silently ignored, since all tools 164 /// work well with UTF-8. 165 /// This function assumes that you only use UTF-8 *text* data and will convert 166 /// it to your desired encoding before writing to the file. 167 /// 168 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 169 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 170 /// our best shot to make gcc/ld understand international characters. This 171 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 172 /// 173 /// \returns non-zero error_code if failed 174 std::error_code 175 writeFileWithEncoding(StringRef FileName, StringRef Contents, 176 WindowsEncodingMethod Encoding = WEM_UTF8); 177 178 /// This function waits for the process specified by \p PI to finish. 179 /// \returns A \see ProcessInfo struct with Pid set to: 180 /// \li The process id of the child process if the child process has changed 181 /// state. 182 /// \li 0 if the child process has not changed state. 183 /// \note Users of this function should always check the ReturnCode member of 184 /// the \see ProcessInfo returned from this function. 185 ProcessInfo Wait( 186 const ProcessInfo &PI, ///< The child process that should be waited on. 187 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 188 ///< time to wait for the child process to exit. If the time expires, the 189 ///< child is killed and this function returns. If zero, this function 190 ///< will perform a non-blocking wait on the child process. 191 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 192 ///< until child has terminated. 193 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a 194 ///< string instance in which error messages will be returned. If the 195 ///< string is non-empty upon return an error occurred while invoking the 196 ///< program. 197 ); 198 199 #if defined(_WIN32) 200 /// Given a list of command line arguments, quote and escape them as necessary 201 /// to build a single flat command line appropriate for calling CreateProcess 202 /// on 203 /// Windows. 204 std::string flattenWindowsCommandLine(ArrayRef<StringRef> Args); 205 #endif 206 } 207 } 208 209 #endif 210