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/Path.h" 19 #include <system_error> 20 21 namespace llvm { 22 namespace sys { 23 24 /// This is the OS-specific separator for PATH like environment variables: 25 // a colon on Unix or a semicolon on Windows. 26 #if defined(LLVM_ON_UNIX) 27 const char EnvPathSeparator = ':'; 28 #elif defined (LLVM_ON_WIN32) 29 const char EnvPathSeparator = ';'; 30 #endif 31 32 /// @brief This struct encapsulates information about a process. 33 struct ProcessInfo { 34 #if defined(LLVM_ON_UNIX) 35 typedef pid_t ProcessId; 36 #elif defined(LLVM_ON_WIN32) 37 typedef unsigned long ProcessId; // Must match the type of DWORD on Windows. 38 typedef void * HANDLE; // Must match the type of HANDLE on Windows. 39 /// The handle to the process (available on Windows only). 40 HANDLE ProcessHandle; 41 #else 42 #error "ProcessInfo is not defined for this platform!" 43 #endif 44 45 /// The process identifier. 46 ProcessId Pid; 47 48 /// The return code, set after execution. 49 int ReturnCode; 50 51 ProcessInfo(); 52 }; 53 54 /// This function attempts to locate a program in the operating 55 /// system's file system using some pre-determined set of locations to search 56 /// (e.g. the PATH on Unix). Paths with slashes are returned unmodified. 57 /// 58 /// It 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 /// @returns A string containing the path of the program or an empty string if 63 /// the program could not be found. 64 std::string FindProgramByName(const std::string& name); 65 66 // These functions change the specified standard stream (stdin or stdout) to 67 // binary mode. They return errc::success if the specified stream 68 // was changed. Otherwise a platform dependent error is returned. 69 std::error_code ChangeStdinToBinary(); 70 std::error_code ChangeStdoutToBinary(); 71 72 /// This function executes the program using the arguments provided. The 73 /// invoked program will inherit the stdin, stdout, and stderr file 74 /// descriptors, the environment and other configuration settings of the 75 /// invoking program. 76 /// This function waits for the program to finish, so should be avoided in 77 /// library functions that aren't expected to block. Consider using 78 /// ExecuteNoWait() instead. 79 /// @returns an integer result code indicating the status of the program. 80 /// A zero or positive value indicates the result code of the program. 81 /// -1 indicates failure to execute 82 /// -2 indicates a crash during execution or timeout 83 int ExecuteAndWait( 84 StringRef Program, ///< Path of the program to be executed. It is 85 /// presumed this is the result of the FindProgramByName method. 86 const char **args, ///< A vector of strings that are passed to the 87 ///< program. The first element should be the name of the program. 88 ///< The list *must* be terminated by a null char* entry. 89 const char **env = nullptr, ///< An optional vector of strings to use for 90 ///< the program's environment. If not provided, the current program's 91 ///< environment will be used. 92 const StringRef **redirects = nullptr, ///< An optional array of pointers 93 ///< to paths. If the array is null, no redirection is done. The array 94 ///< should have a size of at least three. The inferior process's 95 ///< stdin(0), stdout(1), and stderr(2) will be redirected to the 96 ///< corresponding paths. 97 ///< When an empty path is passed in, the corresponding file 98 ///< descriptor will be disconnected (ie, /dev/null'd) in a portable 99 ///< way. 100 unsigned secondsToWait = 0, ///< If non-zero, this specifies the amount 101 ///< of time to wait for the child process to exit. If the time 102 ///< expires, the child is killed and this call returns. If zero, 103 ///< this function will wait until the child finishes or forever if 104 ///< it doesn't. 105 unsigned memoryLimit = 0, ///< If non-zero, this specifies max. amount 106 ///< of memory can be allocated by process. If memory usage will be 107 ///< higher limit, the child is killed and this call returns. If zero 108 ///< - no memory limit. 109 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a 110 ///< string instance in which error messages will be returned. If the 111 ///< string is non-empty upon return an error occurred while invoking the 112 ///< program. 113 bool *ExecutionFailed = nullptr); 114 115 /// Similar to ExecuteAndWait, but returns immediately. 116 /// @returns The \see ProcessInfo of the newly launced process. 117 /// \note On Microsoft Windows systems, users will need to either call \see 118 /// Wait until the process finished execution or win32 CloseHandle() API on 119 /// ProcessInfo.ProcessHandle to avoid memory leaks. 120 ProcessInfo 121 ExecuteNoWait(StringRef Program, const char **args, const char **env = nullptr, 122 const StringRef **redirects = nullptr, unsigned memoryLimit = 0, 123 std::string *ErrMsg = nullptr, bool *ExecutionFailed = nullptr); 124 125 /// Return true if the given arguments fit within system-specific 126 /// argument length limits. 127 bool argumentsFitWithinSystemLimits(ArrayRef<const char*> Args); 128 129 /// This function waits for the process specified by \p PI to finish. 130 /// \returns A \see ProcessInfo struct with Pid set to: 131 /// \li The process id of the child process if the child process has changed 132 /// state. 133 /// \li 0 if the child process has not changed state. 134 /// \note Users of this function should always check the ReturnCode member of 135 /// the \see ProcessInfo returned from this function. 136 ProcessInfo Wait( 137 const ProcessInfo &PI, ///< The child process that should be waited on. 138 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of 139 ///< time to wait for the child process to exit. If the time expires, the 140 ///< child is killed and this function returns. If zero, this function 141 ///< will perform a non-blocking wait on the child process. 142 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits 143 ///< until child has terminated. 144 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a 145 ///< string instance in which error messages will be returned. If the 146 ///< string is non-empty upon return an error occurred while invoking the 147 ///< program. 148 ); 149 } 150 } 151 152 #endif 153
