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/Support/ErrorOr.h" 19 #include <system_error> 20 21 namespace llvm { 22 class StringRef; 23 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 (LLVM_ON_WIN32) 31 const char EnvPathSeparator = ';'; 32 #endif 33 34 /// @brief This struct encapsulates information about a process. 35 struct ProcessInfo { 36 #if defined(LLVM_ON_UNIX) 37 typedef pid_t ProcessId; 38 #elif defined(LLVM_ON_WIN32) 39 typedef unsigned long ProcessId; // Must match the type of DWORD on Windows. 40 typedef void * HANDLE; // Must match the type of HANDLE on Windows. 41 /// The handle to the process (available on Windows only). 42 HANDLE ProcessHandle; 43 #else 44 #error "ProcessInfo is not defined for this platform!" 45 #endif 46 47 enum : ProcessId { InvalidPid = 0 }; 48 49 /// The process identifier. 50 ProcessId Pid; 51 52 /// The return code, set after execution. 53 int ReturnCode; 54 55 ProcessInfo(); 56 }; 57 58 /// \brief Find the first executable file \p Name in \p Paths. 59 /// 60 /// This does not perform hashing as a shell would but instead stats each PATH 61 /// entry individually so should generally be avoided. Core LLVM library 62 /// functions and options should instead require fully specified paths. 63 /// 64 /// \param Name name of the executable to find. If it contains any system 65 /// slashes, it will be returned as is. 66 /// \param Paths optional list of paths to search for \p Name. If empty it 67 /// will use the system PATH environment instead. 68 /// 69 /// \returns The fully qualified path to the first \p Name in \p Paths if it 70 /// exists. \p Name if \p Name has slashes in it. Otherwise an error. 71 ErrorOr<std::string> 72 findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = None); 73 74 // These functions change the specified standard stream (stdin or stdout) to 75 // binary mode. They return errc::success if the specified stream 76 // was changed. Otherwise a platform dependent error is returned. 77 std::error_code ChangeStdinToBinary(); 78 std::error_code ChangeStdoutToBinary(); 79 80 /// This function executes the program using the arguments provided. The 81 /// invoked program will inherit the stdin, stdout, and stderr file 82 /// descriptors, the environment and other configuration settings of the 83 /// invoking program. 84 /// This function waits for the program to finish, so should be avoided in 85 /// library functions that aren't expected to block. Consider using 86 /// ExecuteNoWait() instead. 87 /// @returns an integer result code indicating the status of the program. 88 /// A zero or positive value indicates the result code of the program. 89 /// -1 indicates failure to execute 90 /// -2 indicates a crash during execution or timeout 91 int ExecuteAndWait( 92 StringRef Program, ///< Path of the program to be executed. It is 93 ///< presumed this is the result of the findProgramByName method. 94 const char **args, ///< A vector of strings that are passed to the 95 ///< program. The first element should be the name of the program. 96 ///< The list *must* be terminated by a null char* entry. 97 const char **env = nullptr, ///< An optional vector of strings to use for 98 ///< the program's environment. If not provided, the current program's 99 ///< environment will be used. 100 const StringRef **redirects = nullptr, ///< An optional array of pointers 101 ///< to paths. If the array is null, no redirection is done. The array 102 ///< should have a size of at least three. The inferior process's 103 ///< stdin(0), stdout(1), and stderr(2) will be redirected to the 104 ///< corresponding paths. 105 ///< When an empty path is passed in, the corresponding file 106 ///< descriptor will be disconnected (ie, /dev/null'd) in a portable 107 ///< way. 108 unsigned secondsToWait = 0, ///< If non-zero, this specifies the amount 109 ///< of time to wait for the child process to exit. If the time 110 ///< expires, the child is killed and this call returns. If zero, 111 ///< this function will wait until the child finishes or forever if 112 ///< it doesn't. 113 unsigned memoryLimit = 0, ///< If non-zero, this specifies max. amount 114 ///< of memory can be allocated by process. If memory usage will be 115 ///< higher limit, the child is killed and this call returns. If zero 116 ///< - no memory limit. 117 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 118 ///< string instance in which error messages will be returned. If the 119 ///< string is non-empty upon return an error occurred while invoking the 120 ///< program. 121 bool *ExecutionFailed = nullptr); 122 123 /// Similar to ExecuteAndWait, but returns immediately. 124 /// @returns The \see ProcessInfo of the newly launced process. 125 /// \note On Microsoft Windows systems, users will need to either call \see 126 /// Wait until the process finished execution or win32 CloseHandle() API on 127 /// ProcessInfo.ProcessHandle to avoid memory leaks. 128 ProcessInfo 129 ExecuteNoWait(StringRef Program, const char **args, const char **env = nullptr, 130 const StringRef **redirects = nullptr, unsigned memoryLimit = 0, 131 std::string *ErrMsg = nullptr, bool *ExecutionFailed = nullptr); 132 133 /// Return true if the given arguments fit within system-specific 134 /// argument length limits. 135 bool commandLineFitsWithinSystemLimits(StringRef Program, ArrayRef<const char*> Args); 136 137 /// File encoding options when writing contents that a non-UTF8 tool will 138 /// read (on Windows systems). For UNIX, we always use UTF-8. 139 enum WindowsEncodingMethod { 140 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 141 /// encoding conversion". 142 WEM_UTF8, 143 WEM_CurrentCodePage, 144 WEM_UTF16 145 }; 146 147 /// Saves the UTF8-encoded \p contents string into the file \p FileName 148 /// using a specific encoding. 149 /// 150 /// This write file function adds the possibility to choose which encoding 151 /// to use when writing a text file. On Windows, this is important when 152 /// writing files with internationalization support with an encoding that is 153 /// different from the one used in LLVM (UTF-8). We use this when writing 154 /// response files, since GCC tools on MinGW only understand legacy code 155 /// pages, and VisualStudio tools only understand UTF-16. 156 /// For UNIX, using different encodings is silently ignored, since all tools 157 /// work well with UTF-8. 158 /// This function assumes that you only use UTF-8 *text* data and will convert 159 /// it to your desired encoding before writing to the file. 160 /// 161 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 162 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 163 /// our best shot to make gcc/ld understand international characters. This 164 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 165 /// 166 /// \returns non-zero error_code if failed 167 std::error_code 168 writeFileWithEncoding(StringRef FileName, StringRef Contents, 169 WindowsEncodingMethod Encoding = WEM_UTF8); 170 171 /// This function waits for the process specified by \p PI to finish. 172 /// \returns A \see ProcessInfo struct with Pid set to: 173 /// \li The process id of the child process if the child process has changed 174 /// state. 175 /// \li 0 if the child process has not changed state. 176 /// \note Users of this function should always check the ReturnCode member of 177 /// the \see ProcessInfo returned from this function. 178 ProcessInfo Wait( 179 const ProcessInfo &PI, ///< The child process that should be waited on. 180 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 181 ///< time to wait for the child process to exit. If the time expires, the 182 ///< child is killed and this function returns. If zero, this function 183 ///< will perform a non-blocking wait on the child process. 184 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 185 ///< until child has terminated. 186 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a 187 ///< string instance in which error messages will be returned. If the 188 ///< string is non-empty upon return an error occurred while invoking the 189 ///< program. 190 ); 191 } 192 } 193 194 #endif 195
