1 //===- llvm/Support/Program.h ------------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the llvm::sys::Program class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SUPPORT_PROGRAM_H
15 #define LLVM_SUPPORT_PROGRAM_H
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/Support/Path.h"
19 #include <system_error>
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 = ';';
32 /// @brief This struct encapsulates information about a process.
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).
42 #error "ProcessInfo is not defined for this platform!"
45 /// The process identifier.
48 /// The return code, set after execution.
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.
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.
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);
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();
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
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
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
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
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
113 bool *ExecutionFailed = nullptr);
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.
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);
125 /// Return true if the given arguments fit within system-specific
126 /// argument length limits.
127 bool argumentsFitWithinSystemLimits(ArrayRef<const char*> Args);
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
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.
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