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 /// The process identifier. 48 ProcessId Pid; 49 50 /// The return code, set after execution. 51 int ReturnCode; 52 53 ProcessInfo(); 54 }; 55 56 /// \brief 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 = None); 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 const char **args, ///< A vector of strings that are passed to the 93 ///< program. The first element should be the name of the program. 94 ///< The list *must* be terminated by a null char* entry. 95 const char **env = nullptr, ///< An optional vector of strings to use for 96 ///< the program's environment. If not provided, the current program's 97 ///< environment will be used. 98 const StringRef **redirects = nullptr, ///< An optional array of pointers 99 ///< to paths. If the array is null, no redirection is done. The array 100 ///< should have a size of at least three. The inferior process's 101 ///< stdin(0), stdout(1), and stderr(2) will be redirected to the 102 ///< corresponding paths. 103 ///< When an empty path is passed in, the corresponding file 104 ///< descriptor will be disconnected (ie, /dev/null'd) in a portable 105 ///< 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 \see 124 /// Wait until the process finished execution or win32 CloseHandle() API on 125 /// ProcessInfo.ProcessHandle to avoid memory leaks. 126 ProcessInfo 127 ExecuteNoWait(StringRef Program, const char **args, const char **env = nullptr, 128 const StringRef **redirects = nullptr, unsigned memoryLimit = 0, 129 std::string *ErrMsg = nullptr, bool *ExecutionFailed = nullptr); 130 131 /// Return true if the given arguments fit within system-specific 132 /// argument length limits. 133 bool argumentsFitWithinSystemLimits(ArrayRef<const char*> Args); 134 135 /// File encoding options when writing contents that a non-UTF8 tool will 136 /// read (on Windows systems). For UNIX, we always use UTF-8. 137 enum WindowsEncodingMethod { 138 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 139 /// encoding conversion". 140 WEM_UTF8, 141 WEM_CurrentCodePage, 142 WEM_UTF16 143 }; 144 145 /// Saves the UTF8-encoded \p contents string into the file \p FileName 146 /// using a specific encoding. 147 /// 148 /// This write file function adds the possibility to choose which encoding 149 /// to use when writing a text file. On Windows, this is important when 150 /// writing files with internationalization support with an encoding that is 151 /// different from the one used in LLVM (UTF-8). We use this when writing 152 /// response files, since GCC tools on MinGW only understand legacy code 153 /// pages, and VisualStudio tools only understand UTF-16. 154 /// For UNIX, using different encodings is silently ignored, since all tools 155 /// work well with UTF-8. 156 /// This function assumes that you only use UTF-8 *text* data and will convert 157 /// it to your desired encoding before writing to the file. 158 /// 159 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 160 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 161 /// our best shot to make gcc/ld understand international characters. This 162 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 163 /// 164 /// \returns non-zero error_code if failed 165 std::error_code 166 writeFileWithEncoding(StringRef FileName, StringRef Contents, 167 WindowsEncodingMethod Encoding = WEM_UTF8); 168 169 /// This function waits for the process specified by \p PI to finish. 170 /// \returns A \see ProcessInfo struct with Pid set to: 171 /// \li The process id of the child process if the child process has changed 172 /// state. 173 /// \li 0 if the child process has not changed state. 174 /// \note Users of this function should always check the ReturnCode member of 175 /// the \see ProcessInfo returned from this function. 176 ProcessInfo Wait( 177 const ProcessInfo &PI, ///< The child process that should be waited on. 178 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 179 ///< time to wait for the child process to exit. If the time expires, the 180 ///< child is killed and this function returns. If zero, this function 181 ///< will perform a non-blocking wait on the child process. 182 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 183 ///< until child has terminated. 184 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a 185 ///< string instance in which error messages will be returned. If the 186 ///< string is non-empty upon return an error occurred while invoking the 187 ///< program. 188 ); 189 } 190 } 191 192 #endif 193