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