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/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 (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 = {}); 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 ArrayRef<Optional<StringRef>> Redirects = {}, ///< 101 ///< An array of optional paths. Should have a size of zero or three. 102 ///< If the array is empty, no redirections are performed. 103 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2) 104 ///< will be redirected to the corresponding paths, if the optional path 105 ///< is present (not \c llvm::None). 106 ///< When an empty path is passed in, the corresponding file descriptor 107 ///< will be disconnected (ie, /dev/null'd) in a portable 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 126 /// \see Wait until the process finished execution or win32 CloseHandle() API 127 /// on ProcessInfo.ProcessHandle to avoid memory leaks. 128 ProcessInfo ExecuteNoWait(StringRef Program, const char **Args, 129 const char **Env = nullptr, 130 ArrayRef<Optional<StringRef>> Redirects = {}, 131 unsigned MemoryLimit = 0, 132 std::string *ErrMsg = nullptr, 133 bool *ExecutionFailed = nullptr); 134 135 /// Return true if the given arguments fit within system-specific 136 /// argument length limits. 137 bool commandLineFitsWithinSystemLimits(StringRef Program, 138 ArrayRef<const char *> Args); 139 140 /// File encoding options when writing contents that a non-UTF8 tool will 141 /// read (on Windows systems). For UNIX, we always use UTF-8. 142 enum WindowsEncodingMethod { 143 /// UTF-8 is the LLVM native encoding, being the same as "do not perform 144 /// encoding conversion". 145 WEM_UTF8, 146 WEM_CurrentCodePage, 147 WEM_UTF16 148 }; 149 150 /// Saves the UTF8-encoded \p contents string into the file \p FileName 151 /// using a specific encoding. 152 /// 153 /// This write file function adds the possibility to choose which encoding 154 /// to use when writing a text file. On Windows, this is important when 155 /// writing files with internationalization support with an encoding that is 156 /// different from the one used in LLVM (UTF-8). We use this when writing 157 /// response files, since GCC tools on MinGW only understand legacy code 158 /// pages, and VisualStudio tools only understand UTF-16. 159 /// For UNIX, using different encodings is silently ignored, since all tools 160 /// work well with UTF-8. 161 /// This function assumes that you only use UTF-8 *text* data and will convert 162 /// it to your desired encoding before writing to the file. 163 /// 164 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in 165 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is 166 /// our best shot to make gcc/ld understand international characters. This 167 /// should be changed as soon as binutils fix this to support UTF16 on mingw. 168 /// 169 /// \returns non-zero error_code if failed 170 std::error_code 171 writeFileWithEncoding(StringRef FileName, StringRef Contents, 172 WindowsEncodingMethod Encoding = WEM_UTF8); 173 174 /// This function waits for the process specified by \p PI to finish. 175 /// \returns A \see ProcessInfo struct with Pid set to: 176 /// \li The process id of the child process if the child process has changed 177 /// state. 178 /// \li 0 if the child process has not changed state. 179 /// \note Users of this function should always check the ReturnCode member of 180 /// the \see ProcessInfo returned from this function. 181 ProcessInfo Wait( 182 const ProcessInfo &PI, ///< The child process that should be waited on. 183 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 184 ///< time to wait for the child process to exit. If the time expires, the 185 ///< child is killed and this function returns. If zero, this function 186 ///< will perform a non-blocking wait on the child process. 187 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 188 ///< until child has terminated. 189 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a 190 ///< string instance in which error messages will be returned. If the 191 ///< string is non-empty upon return an error occurred while invoking the 192 ///< program. 193 ); 194 } 195 } 196 197 #endif 198
