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, 71 ArrayRef<StringRef> Paths = ArrayRef<StringRef>()); 72 73 // These functions change the specified standard stream (stdin or stdout) to 74 // binary mode. They return errc::success if the specified stream 75 // was changed. Otherwise a platform dependent error is returned. 76 std::error_code ChangeStdinToBinary(); 77 std::error_code ChangeStdoutToBinary(); 78 79 /// This function executes the program using the arguments provided. The 80 /// invoked program will inherit the stdin, stdout, and stderr file 81 /// descriptors, the environment and other configuration settings of the 82 /// invoking program. 83 /// This function waits for the program to finish, so should be avoided in 84 /// library functions that aren't expected to block. Consider using 85 /// ExecuteNoWait() instead. 86 /// @returns an integer result code indicating the status of the program. 87 /// A zero or positive value indicates the result code of the program. 88 /// -1 indicates failure to execute 89 /// -2 indicates a crash during execution or timeout 90 int ExecuteAndWait( 91 StringRef Program, ///< Path of the program to be executed. It is 92 /// presumed this is the result of the findProgramByName method. 93 const char **args, ///< A vector of strings that are passed to the 94 ///< program. The first element should be the name of the program. 95 ///< The list *must* be terminated by a null char* entry. 96 const char **env = nullptr, ///< An optional vector of strings to use for 97 ///< the program's environment. If not provided, the current program's 98 ///< environment will be used. 99 const StringRef **redirects = nullptr, ///< An optional array of pointers 100 ///< to paths. If the array is null, no redirection is done. The array 101 ///< should have a size of at least three. The inferior process's 102 ///< stdin(0), stdout(1), and stderr(2) will be redirected to the 103 ///< corresponding paths. 104 ///< When an empty path is passed in, the corresponding file 105 ///< descriptor will be disconnected (ie, /dev/null'd) in a portable 106 ///< 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 \see 125 /// Wait until the process finished execution or win32 CloseHandle() API on 126 /// ProcessInfo.ProcessHandle to avoid memory leaks. 127 ProcessInfo 128 ExecuteNoWait(StringRef Program, const char **args, const char **env = nullptr, 129 const StringRef **redirects = nullptr, unsigned memoryLimit = 0, 130 std::string *ErrMsg = nullptr, bool *ExecutionFailed = nullptr); 131 132 /// Return true if the given arguments fit within system-specific 133 /// argument length limits. 134 bool argumentsFitWithinSystemLimits(ArrayRef<const char*> Args); 135 136 /// File encoding options when writing contents that a non-UTF8 tool will 137 /// read (on Windows systems). For UNIX, we always use UTF-8. 138 enum WindowsEncodingMethod { 139 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 140 /// encoding conversion". 141 WEM_UTF8, 142 WEM_CurrentCodePage, 143 WEM_UTF16 144 }; 145 146 /// Saves the UTF8-encoded \p contents string into the file \p FileName 147 /// using a specific encoding. 148 /// 149 /// This write file function adds the possibility to choose which encoding 150 /// to use when writing a text file. On Windows, this is important when 151 /// writing files with internationalization support with an encoding that is 152 /// different from the one used in LLVM (UTF-8). We use this when writing 153 /// response files, since GCC tools on MinGW only understand legacy code 154 /// pages, and VisualStudio tools only understand UTF-16. 155 /// For UNIX, using different encodings is silently ignored, since all tools 156 /// work well with UTF-8. 157 /// This function assumes that you only use UTF-8 *text* data and will convert 158 /// it to your desired encoding before writing to the file. 159 /// 160 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 161 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 162 /// our best shot to make gcc/ld understand international characters. This 163 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 164 /// 165 /// \returns non-zero error_code if failed 166 std::error_code 167 writeFileWithEncoding(StringRef FileName, StringRef Contents, 168 WindowsEncodingMethod Encoding = WEM_UTF8); 169 170 /// This function waits for the process specified by \p PI to finish. 171 /// \returns A \see ProcessInfo struct with Pid set to: 172 /// \li The process id of the child process if the child process has changed 173 /// state. 174 /// \li 0 if the child process has not changed state. 175 /// \note Users of this function should always check the ReturnCode member of 176 /// the \see ProcessInfo returned from this function. 177 ProcessInfo Wait( 178 const ProcessInfo &PI, ///< The child process that should be waited on. 179 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 180 ///< time to wait for the child process to exit. If the time expires, the 181 ///< child is killed and this function returns. If zero, this function 182 ///< will perform a non-blocking wait on the child process. 183 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 184 ///< until child has terminated. 185 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a 186 ///< string instance in which error messages will be returned. If the 187 ///< string is non-empty upon return an error occurred while invoking the 188 ///< program. 189 ); 190 } 191 } 192 193 #endif 194