1 | //===- llvm/Support/Program.h ------------------------------------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // This file declares the llvm::sys::Program class. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #ifndef LLVM_SUPPORT_PROGRAM_H |
14 | #define LLVM_SUPPORT_PROGRAM_H |
15 | |
16 | #include "llvm/ADT/ArrayRef.h" |
17 | #include "llvm/ADT/StringRef.h" |
18 | #include "llvm/Config/llvm-config.h" |
19 | #include "llvm/Support/ErrorOr.h" |
20 | #include "llvm/Support/FileSystem.h" |
21 | #include <chrono> |
22 | #include <optional> |
23 | #include <system_error> |
24 | |
25 | namespace llvm { |
26 | class BitVector; |
27 | namespace sys { |
28 | |
29 | /// This is the OS-specific separator for PATH like environment variables: |
30 | // a colon on Unix or a semicolon on Windows. |
31 | #if defined(LLVM_ON_UNIX) |
32 | const char EnvPathSeparator = ':'; |
33 | #elif defined (_WIN32) |
34 | const char EnvPathSeparator = ';'; |
35 | #endif |
36 | |
37 | #if defined(_WIN32) |
38 | typedef unsigned long procid_t; // Must match the type of DWORD on Windows. |
39 | typedef void *process_t; // Must match the type of HANDLE on Windows. |
40 | #else |
41 | typedef ::pid_t procid_t; |
42 | typedef procid_t process_t; |
43 | #endif |
44 | |
45 | /// This struct encapsulates information about a process. |
46 | struct ProcessInfo { |
47 | enum : procid_t { InvalidPid = 0 }; |
48 | |
49 | procid_t Pid; /// The process identifier. |
50 | process_t Process; /// Platform-dependent process object. |
51 | |
52 | /// The return code, set after execution. |
53 | int ReturnCode; |
54 | |
55 | ProcessInfo(); |
56 | }; |
57 | |
58 | /// This struct encapsulates information about a process execution. |
59 | struct ProcessStatistics { |
60 | std::chrono::microseconds TotalTime; |
61 | std::chrono::microseconds UserTime; |
62 | uint64_t PeakMemory = 0; ///< Maximum resident set size in KiB. |
63 | }; |
64 | |
65 | /// Find the first executable file \p Name in \p Paths. |
66 | /// |
67 | /// This does not perform hashing as a shell would but instead stats each PATH |
68 | /// entry individually so should generally be avoided. Core LLVM library |
69 | /// functions and options should instead require fully specified paths. |
70 | /// |
71 | /// \param Name name of the executable to find. If it contains any system |
72 | /// slashes, it will be returned as is. |
73 | /// \param Paths optional list of paths to search for \p Name. If empty it |
74 | /// will use the system PATH environment instead. |
75 | /// |
76 | /// \returns The fully qualified path to the first \p Name in \p Paths if it |
77 | /// exists. \p Name if \p Name has slashes in it. Otherwise an error. |
78 | ErrorOr<std::string> |
79 | findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {}); |
80 | |
81 | // These functions change the specified standard stream (stdin or stdout) mode |
82 | // based on the Flags. They return errc::success if the specified stream was |
83 | // changed. Otherwise, a platform dependent error is returned. |
84 | std::error_code ChangeStdinMode(fs::OpenFlags Flags); |
85 | std::error_code ChangeStdoutMode(fs::OpenFlags Flags); |
86 | |
87 | // These functions change the specified standard stream (stdin or stdout) to |
88 | // binary mode. They return errc::success if the specified stream |
89 | // was changed. Otherwise a platform dependent error is returned. |
90 | std::error_code ChangeStdinToBinary(); |
91 | std::error_code ChangeStdoutToBinary(); |
92 | |
93 | /// This function executes the program using the arguments provided. The |
94 | /// invoked program will inherit the stdin, stdout, and stderr file |
95 | /// descriptors, the environment and other configuration settings of the |
96 | /// invoking program. |
97 | /// This function waits for the program to finish, so should be avoided in |
98 | /// library functions that aren't expected to block. Consider using |
99 | /// ExecuteNoWait() instead. |
100 | /// \returns an integer result code indicating the status of the program. |
101 | /// A zero or positive value indicates the result code of the program. |
102 | /// -1 indicates failure to execute |
103 | /// -2 indicates a crash during execution or timeout |
104 | int ExecuteAndWait( |
105 | StringRef Program, ///< Path of the program to be executed. It is |
106 | ///< presumed this is the result of the findProgramByName method. |
107 | ArrayRef<StringRef> Args, ///< An array of strings that are passed to the |
108 | ///< program. The first element should be the name of the program. |
109 | ///< The array should **not** be terminated by an empty StringRef. |
110 | std::optional<ArrayRef<StringRef>> Env = |
111 | std::nullopt, ///< An optional vector of |
112 | ///< strings to use for the program's environment. If not provided, the |
113 | ///< current program's environment will be used. If specified, the |
114 | ///< vector should **not** be terminated by an empty StringRef. |
115 | ArrayRef<std::optional<StringRef>> Redirects = {}, ///< |
116 | ///< An array of optional paths. Should have a size of zero or three. |
117 | ///< If the array is empty, no redirections are performed. |
118 | ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2) |
119 | ///< will be redirected to the corresponding paths, if the optional path |
120 | ///< is present (not \c std::nullopt). |
121 | ///< When an empty path is passed in, the corresponding file descriptor |
122 | ///< will be disconnected (ie, /dev/null'd) in a portable way. |
123 | unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount |
124 | ///< of time to wait for the child process to exit. If the time |
125 | ///< expires, the child is killed and this call returns. If zero, |
126 | ///< this function will wait until the child finishes or forever if |
127 | ///< it doesn't. |
128 | unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount |
129 | ///< of memory can be allocated by process. If memory usage will be |
130 | ///< higher limit, the child is killed and this call returns. If zero |
131 | ///< - no memory limit. |
132 | std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a |
133 | ///< string instance in which error messages will be returned. If the |
134 | ///< string is non-empty upon return an error occurred while invoking the |
135 | ///< program. |
136 | bool *ExecutionFailed = nullptr, |
137 | std::optional<ProcessStatistics> *ProcStat = nullptr, ///< If non-zero, |
138 | /// provides a pointer to a structure in which process execution |
139 | /// statistics will be stored. |
140 | BitVector *AffinityMask = nullptr ///< CPUs or processors the new |
141 | /// program shall run on. |
142 | ); |
143 | |
144 | /// Similar to \ref ExecuteAndWait, but returns immediately. |
145 | /// \returns The \ref ProcessInfo of the newly launched process. |
146 | /// \note On Microsoft Windows systems, users will need to either call |
147 | /// \ref Wait until the process has finished executing or win32's CloseHandle |
148 | /// API on ProcessInfo.ProcessHandle to avoid memory leaks. |
149 | ProcessInfo ExecuteNoWait( |
150 | StringRef Program, ArrayRef<StringRef> Args, |
151 | std::optional<ArrayRef<StringRef>> Env, |
152 | ArrayRef<std::optional<StringRef>> Redirects = {}, |
153 | unsigned MemoryLimit = 0, std::string *ErrMsg = nullptr, |
154 | bool *ExecutionFailed = nullptr, BitVector *AffinityMask = nullptr, |
155 | /// If true the executed program detatches from the controlling |
156 | /// terminal. I/O streams such as llvm::outs, llvm::errs, and stdin will |
157 | /// be closed until redirected to another output location |
158 | bool DetachProcess = false); |
159 | |
160 | /// Return true if the given arguments fit within system-specific |
161 | /// argument length limits. |
162 | bool commandLineFitsWithinSystemLimits(StringRef Program, |
163 | ArrayRef<StringRef> Args); |
164 | |
165 | /// Return true if the given arguments fit within system-specific |
166 | /// argument length limits. |
167 | bool commandLineFitsWithinSystemLimits(StringRef Program, |
168 | ArrayRef<const char *> Args); |
169 | |
170 | /// File encoding options when writing contents that a non-UTF8 tool will |
171 | /// read (on Windows systems). For UNIX, we always use UTF-8. |
172 | enum WindowsEncodingMethod { |
173 | /// UTF-8 is the LLVM native encoding, being the same as "do not perform |
174 | /// encoding conversion". |
175 | WEM_UTF8, |
176 | WEM_CurrentCodePage, |
177 | WEM_UTF16 |
178 | }; |
179 | |
180 | /// Saves the UTF8-encoded \p contents string into the file \p FileName |
181 | /// using a specific encoding. |
182 | /// |
183 | /// This write file function adds the possibility to choose which encoding |
184 | /// to use when writing a text file. On Windows, this is important when |
185 | /// writing files with internationalization support with an encoding that is |
186 | /// different from the one used in LLVM (UTF-8). We use this when writing |
187 | /// response files, since GCC tools on MinGW only understand legacy code |
188 | /// pages, and VisualStudio tools only understand UTF-16. |
189 | /// For UNIX, using different encodings is silently ignored, since all tools |
190 | /// work well with UTF-8. |
191 | /// This function assumes that you only use UTF-8 *text* data and will convert |
192 | /// it to your desired encoding before writing to the file. |
193 | /// |
194 | /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in |
195 | /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is |
196 | /// our best shot to make gcc/ld understand international characters. This |
197 | /// should be changed as soon as binutils fix this to support UTF16 on mingw. |
198 | /// |
199 | /// \returns non-zero error_code if failed |
200 | std::error_code |
201 | writeFileWithEncoding(StringRef FileName, StringRef Contents, |
202 | WindowsEncodingMethod Encoding = WEM_UTF8); |
203 | |
204 | /// This function waits for the process specified by \p PI to finish. |
205 | /// \returns A \see ProcessInfo struct with Pid set to: |
206 | /// \li The process id of the child process if the child process has changed |
207 | /// state. |
208 | /// \li 0 if the child process has not changed state. |
209 | /// \note Users of this function should always check the ReturnCode member of |
210 | /// the \see ProcessInfo returned from this function. |
211 | ProcessInfo |
212 | Wait(const ProcessInfo &PI, ///< The child process that should be waited on. |
213 | std::optional<unsigned> SecondsToWait, ///< If std::nullopt, waits until |
214 | ///< child has terminated. |
215 | ///< If a value, this specifies the amount of time to wait for the child |
216 | ///< process. If the time expires, and \p Polling is false, the child is |
217 | ///< killed and this < function returns. If the time expires and \p |
218 | ///< Polling is true, the child is resumed. |
219 | ///< |
220 | ///< If zero, this function will perform a non-blocking |
221 | ///< wait on the child process. |
222 | std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a |
223 | ///< string instance in which error messages will be returned. If the |
224 | ///< string is non-empty upon return an error occurred while invoking the |
225 | ///< program. |
226 | std::optional<ProcessStatistics> *ProcStat = |
227 | nullptr, ///< If non-zero, provides |
228 | /// a pointer to a structure in which process execution statistics will |
229 | /// be stored. |
230 | |
231 | bool Polling = false ///< If true, do not kill the process on timeout. |
232 | ); |
233 | |
234 | /// Print a command argument, and optionally quote it. |
235 | void printArg(llvm::raw_ostream &OS, StringRef Arg, bool Quote); |
236 | |
237 | #if defined(_WIN32) |
238 | /// Given a list of command line arguments, quote and escape them as necessary |
239 | /// to build a single flat command line appropriate for calling CreateProcess |
240 | /// on |
241 | /// Windows. |
242 | ErrorOr<std::wstring> flattenWindowsCommandLine(ArrayRef<StringRef> Args); |
243 | #endif |
244 | } |
245 | } |
246 | |
247 | #endif |
248 | |