aboutsummaryrefslogtreecommitdiffstats
path: root/include/llvm/Support/Program.h
blob: fb177de97b4092b24707f843525feabac263fd56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
//===- llvm/Support/Program.h ------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the llvm::sys::Program class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_PROGRAM_H
#define LLVM_SUPPORT_PROGRAM_H

#include "llvm/ADT/ArrayRef.h"
#include "llvm/Support/Path.h"

namespace llvm {
class error_code;
namespace sys {

  // TODO: Add operations to communicate with the process, redirect its I/O,
  // etc.

  /// This class provides an abstraction for programs that are executable by the
  /// operating system. It provides a platform generic way to find executable
  /// programs from the path and to execute them in various ways. The sys::Path
  /// class is used to specify the location of the Program.
  /// @since 1.4
  /// @brief An abstraction for finding and executing programs.
  class Program {
    /// Opaque handle for target specific data.
    void *Data_;

    // Noncopyable.
    Program(const Program& other) LLVM_DELETED_FUNCTION;
    Program& operator=(const Program& other) LLVM_DELETED_FUNCTION;

    /// @name Methods
    /// @{

    Program();
    ~Program();

    /// This function executes the program using the \p arguments provided.  The
    /// invoked program will inherit the stdin, stdout, and stderr file
    /// descriptors, the environment and other configuration settings of the
    /// invoking program. If Path::executable() does not return true when this
    /// function is called then a std::string is thrown.
    /// @returns false in case of error, true otherwise.
    /// @see FindProgramByName
    /// @brief Executes the program with the given set of \p args.
    bool Execute
    ( const Path& path,  ///< sys::Path object providing the path of the
      ///< program to be executed. It is presumed this is the result of
      ///< the FindProgramByName method.
      const char** args, ///< A vector of strings that are passed to the
      ///< program.  The first element should be the name of the program.
      ///< The list *must* be terminated by a null char* entry.
      const char ** env = 0, ///< An optional vector of strings to use for
      ///< the program's environment. If not provided, the current program's
      ///< environment will be used.
      const sys::Path** redirects = 0, ///< An optional array of pointers to
      ///< Paths. If the array is null, no redirection is done. The array
      ///< should have a size of at least three. If the pointer in the array
      ///< are not null, then the inferior process's stdin(0), stdout(1),
      ///< and stderr(2) will be redirected to the corresponding Paths.
      ///< When an empty Path is passed in, the corresponding file
      ///< descriptor will be disconnected (ie, /dev/null'd) in a portable
      ///< way.
      unsigned memoryLimit = 0, ///< If non-zero, this specifies max. amount
      ///< of memory can be allocated by process. If memory usage will be
      ///< higher limit, the child is killed and this call returns. If zero
      ///< - no memory limit.
      std::string* ErrMsg = 0 ///< If non-zero, provides a pointer to a string
      ///< instance in which error messages will be returned. If the string
      ///< is non-empty upon return an error occurred while invoking the
      ///< program.
      );

    /// This function waits for the program to exit. This function will block
    /// the current program until the invoked program exits.
    /// @returns an integer result code indicating the status of the program.
    /// A zero or positive value indicates the result code of the program.
    /// -1 indicates failure to execute
    /// -2 indicates a crash during execution or timeout
    /// @see Execute
    /// @brief Waits for the program to exit.
    int Wait
    ( const Path& path, ///< The path to the child process executable.
      unsigned secondsToWait, ///< If non-zero, this specifies the amount
      ///< of time to wait for the child process to exit. If the time
      ///< expires, the child is killed and this call returns. If zero,
      ///< this function will wait until the child finishes or forever if
      ///< it doesn't.
      std::string* ErrMsg ///< If non-zero, provides a pointer to a string
      ///< instance in which error messages will be returned. If the string
      ///< is non-empty upon return an error occurred while waiting.
      );

  public:
    /// This static constructor (factory) will attempt to locate a program in
    /// the operating system's file system using some pre-determined set of
    /// locations to search (e.g. the PATH on Unix). Paths with slashes are
    /// returned unmodified.
    /// @returns A Path object initialized to the path of the program or a
    /// Path object that is empty (invalid) if the program could not be found.
    /// @brief Construct a Program by finding it by name.
    static Path FindProgramByName(const std::string& name);

    // These methods change the specified standard stream (stdin, stdout, or
    // stderr) to binary mode. They return errc::success if the specified stream
    // was changed. Otherwise a platform dependent error is returned.
    static error_code ChangeStdinToBinary();
    static error_code ChangeStdoutToBinary();
    static error_code ChangeStderrToBinary();

    /// A convenience function equivalent to Program prg; prg.Execute(..);
    /// prg.Wait(..);
    /// @see Execute, Wait
    static int ExecuteAndWait(const Path& path,
                              const char** args,
                              const char ** env = 0,
                              const sys::Path** redirects = 0,
                              unsigned secondsToWait = 0,
                              unsigned memoryLimit = 0,
                              std::string* ErrMsg = 0,
                              bool *ExecutionFailed = 0);

    /// A convenience function equivalent to Program prg; prg.Execute(..);
    /// @see Execute
    static void ExecuteNoWait(const Path& path,
                              const char** args,
                              const char ** env = 0,
                              const sys::Path** redirects = 0,
                              unsigned memoryLimit = 0,
                              std::string* ErrMsg = 0);

    /// @}

  };

  // Return true if the given arguments fit within system-specific
  // argument length limits.
  bool argumentsFitWithinSystemLimits(ArrayRef<const char*> Args);
}
}

#endif