LLVM  8.0.0svn
Program.h
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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/Config/llvm-config.h"
21 #include "llvm/Support/ErrorOr.h"
22 #include <system_error>
23 
24 namespace llvm {
25 namespace sys {
26 
27  /// This is the OS-specific separator for PATH like environment variables:
28  // a colon on Unix or a semicolon on Windows.
29 #if defined(LLVM_ON_UNIX)
30  const char EnvPathSeparator = ':';
31 #elif defined (_WIN32)
32  const char EnvPathSeparator = ';';
33 #endif
34 
35 #if defined(_WIN32)
36  typedef unsigned long procid_t; // Must match the type of DWORD on Windows.
37  typedef void *process_t; // Must match the type of HANDLE on Windows.
38 #else
39  typedef pid_t procid_t;
40  typedef procid_t process_t;
41 #endif
42 
43  /// This struct encapsulates information about a process.
44  struct ProcessInfo {
45  enum : procid_t { InvalidPid = 0 };
46 
47  procid_t Pid; /// The process identifier.
48  process_t Process; /// Platform-dependent process object.
49 
50  /// The return code, set after execution.
52 
53  ProcessInfo();
54  };
55 
56  /// Find the first executable file \p Name in \p Paths.
57  ///
58  /// This 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  /// \param Name name of the executable to find. If it contains any system
63  /// slashes, it will be returned as is.
64  /// \param Paths optional list of paths to search for \p Name. If empty it
65  /// will use the system PATH environment instead.
66  ///
67  /// \returns The fully qualified path to the first \p Name in \p Paths if it
68  /// exists. \p Name if \p Name has slashes in it. Otherwise an error.
71 
72  // These functions change the specified standard stream (stdin or stdout) to
73  // binary mode. They return errc::success if the specified stream
74  // was changed. Otherwise a platform dependent error is returned.
75  std::error_code ChangeStdinToBinary();
76  std::error_code ChangeStdoutToBinary();
77 
78  /// This function executes the program using the arguments provided. The
79  /// invoked program will inherit the stdin, stdout, and stderr file
80  /// descriptors, the environment and other configuration settings of the
81  /// invoking program.
82  /// This function waits for the program to finish, so should be avoided in
83  /// library functions that aren't expected to block. Consider using
84  /// ExecuteNoWait() instead.
85  /// \returns an integer result code indicating the status of the program.
86  /// A zero or positive value indicates the result code of the program.
87  /// -1 indicates failure to execute
88  /// -2 indicates a crash during execution or timeout
89  int ExecuteAndWait(
90  StringRef Program, ///< Path of the program to be executed. It is
91  ///< presumed this is the result of the findProgramByName method.
92  ArrayRef<StringRef> Args, ///< An array of strings that are passed to the
93  ///< program. The first element should be the name of the program.
94  ///< The array should **not** be terminated by an empty StringRef.
95  Optional<ArrayRef<StringRef>> Env = None, ///< An optional vector of
96  ///< strings to use for the program's environment. If not provided, the
97  ///< current program's environment will be used. If specified, the
98  ///< vector should **not** be terminated by an empty StringRef.
99  ArrayRef<Optional<StringRef>> Redirects = {}, ///<
100  ///< An array of optional paths. Should have a size of zero or three.
101  ///< If the array is empty, no redirections are performed.
102  ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2)
103  ///< will be redirected to the corresponding paths, if the optional path
104  ///< is present (not \c llvm::None).
105  ///< When an empty path is passed in, the corresponding file descriptor
106  ///< will be disconnected (ie, /dev/null'd) in a portable way.
107  unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount
108  ///< of time to wait for the child process to exit. If the time
109  ///< expires, the child is killed and this call returns. If zero,
110  ///< this function will wait until the child finishes or forever if
111  ///< it doesn't.
112  unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount
113  ///< of memory can be allocated by process. If memory usage will be
114  ///< higher limit, the child is killed and this call returns. If zero
115  ///< - no memory limit.
116  std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a
117  ///< string instance in which error messages will be returned. If the
118  ///< string is non-empty upon return an error occurred while invoking the
119  ///< program.
120  bool *ExecutionFailed = nullptr);
121 
122  /// Similar to ExecuteAndWait, but returns immediately.
123  /// @returns The \see ProcessInfo of the newly launced process.
124  /// \note On Microsoft Windows systems, users will need to either call
125  /// \see Wait until the process finished execution or win32 CloseHandle() API
126  /// on ProcessInfo.ProcessHandle to avoid memory leaks.
129  ArrayRef<Optional<StringRef>> Redirects = {},
130  unsigned MemoryLimit = 0,
131  std::string *ErrMsg = nullptr,
132  bool *ExecutionFailed = nullptr);
133 
134  /// Return true if the given arguments fit within system-specific
135  /// argument length limits.
137  ArrayRef<StringRef> Args);
138 
139  /// Return true if the given arguments fit within system-specific
140  /// argument length limits.
143 
144  /// File encoding options when writing contents that a non-UTF8 tool will
145  /// read (on Windows systems). For UNIX, we always use UTF-8.
147  /// UTF-8 is the LLVM native encoding, being the same as "do not perform
148  /// encoding conversion".
152  };
153 
154  /// Saves the UTF8-encoded \p contents string into the file \p FileName
155  /// using a specific encoding.
156  ///
157  /// This write file function adds the possibility to choose which encoding
158  /// to use when writing a text file. On Windows, this is important when
159  /// writing files with internationalization support with an encoding that is
160  /// different from the one used in LLVM (UTF-8). We use this when writing
161  /// response files, since GCC tools on MinGW only understand legacy code
162  /// pages, and VisualStudio tools only understand UTF-16.
163  /// For UNIX, using different encodings is silently ignored, since all tools
164  /// work well with UTF-8.
165  /// This function assumes that you only use UTF-8 *text* data and will convert
166  /// it to your desired encoding before writing to the file.
167  ///
168  /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in
169  /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is
170  /// our best shot to make gcc/ld understand international characters. This
171  /// should be changed as soon as binutils fix this to support UTF16 on mingw.
172  ///
173  /// \returns non-zero error_code if failed
174  std::error_code
175  writeFileWithEncoding(StringRef FileName, StringRef Contents,
176  WindowsEncodingMethod Encoding = WEM_UTF8);
177 
178  /// This function waits for the process specified by \p PI to finish.
179  /// \returns A \see ProcessInfo struct with Pid set to:
180  /// \li The process id of the child process if the child process has changed
181  /// state.
182  /// \li 0 if the child process has not changed state.
183  /// \note Users of this function should always check the ReturnCode member of
184  /// the \see ProcessInfo returned from this function.
186  const ProcessInfo &PI, ///< The child process that should be waited on.
187  unsigned SecondsToWait, ///< If non-zero, this specifies the amount of
188  ///< time to wait for the child process to exit. If the time expires, the
189  ///< child is killed and this function returns. If zero, this function
190  ///< will perform a non-blocking wait on the child process.
191  bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits
192  ///< until child has terminated.
193  std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a
194  ///< string instance in which error messages will be returned. If the
195  ///< string is non-empty upon return an error occurred while invoking the
196  ///< program.
197  );
198 
199 #if defined(_WIN32)
200  /// Given a list of command line arguments, quote and escape them as necessary
201  /// to build a single flat command line appropriate for calling CreateProcess
202  /// on
203  /// Windows.
204  std::string flattenWindowsCommandLine(ArrayRef<StringRef> Args);
205 #endif
206  }
207 }
208 
209 #endif
Represents either an error or a value T.
Definition: ErrorOr.h:57
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef< StringRef > Args, Optional< ArrayRef< StringRef >> Env, ArrayRef< Optional< StringRef >> Redirects={}, unsigned MemoryLimit=0, std::string *ErrMsg=nullptr, bool *ExecutionFailed=nullptr)
Similar to ExecuteAndWait, but returns immediately.
Definition: Program.cpp:52
std::error_code ChangeStdoutToBinary()
ErrorOr< std::string > findProgramByName(StringRef Name, ArrayRef< StringRef > Paths={})
Find the first executable file Name in Paths.
UTF-8 is the LLVM native encoding, being the same as "do not perform encoding conversion"...
Definition: Program.h:149
int ExecuteAndWait(StringRef Program, ArrayRef< StringRef > Args, Optional< ArrayRef< StringRef >> Env=None, ArrayRef< Optional< StringRef >> Redirects={}, unsigned SecondsToWait=0, unsigned MemoryLimit=0, std::string *ErrMsg=nullptr, bool *ExecutionFailed=nullptr)
This function executes the program using the arguments provided.
Definition: Program.cpp:31
const char EnvPathSeparator
This is the OS-specific separator for PATH like environment variables:
Definition: Program.h:30
procid_t process_t
Definition: Program.h:40
amdgpu Simplify well known AMD library false Value Value const Twine & Name
process_t Process
The process identifier.
Definition: Program.h:48
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
pid_t procid_t
Definition: Program.h:39
bool commandLineFitsWithinSystemLimits(StringRef Program, ArrayRef< StringRef > Args)
Return true if the given arguments fit within system-specific argument length limits.
std::error_code writeFileWithEncoding(StringRef FileName, StringRef Contents, WindowsEncodingMethod Encoding=WEM_UTF8)
Saves the UTF8-encoded contents string into the file FileName using a specific encoding.
WindowsEncodingMethod
File encoding options when writing contents that a non-UTF8 tool will read (on Windows systems)...
Definition: Program.h:146
int ReturnCode
Platform-dependent process object.
Definition: Program.h:51
std::error_code ChangeStdinToBinary()
This struct encapsulates information about a process.
Definition: Program.h:44
Provides ErrorOr<T> smart pointer.
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
ProcessInfo Wait(const ProcessInfo &PI, unsigned SecondsToWait, bool WaitUntilTerminates, std::string *ErrMsg=nullptr)
This function waits for the process specified by PI to finish.
constexpr char Args[]
Key for Kernel::Metadata::mArgs.