1 //===- llvm/Support/Program.h ------------------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file declares the llvm::sys::Program class.
11 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_SUPPORT_PROGRAM_H
14 #define LLVM_SUPPORT_PROGRAM_H
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/Optional.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/Config/llvm-config.h"
20 #include "llvm/Support/ErrorOr.h"
22 #include <system_error>
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 = ';';
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.
39 typedef pid_t procid_t;
40 typedef procid_t process_t;
43 /// This struct encapsulates information about a process.
45 enum : procid_t { InvalidPid = 0 };
47 procid_t Pid; /// The process identifier.
48 process_t Process; /// Platform-dependent process object.
50 /// The return code, set after execution.
56 /// This struct encapsulates information about a process execution.
57 struct ProcessStatistics {
58 std::chrono::microseconds TotalTime;
59 std::chrono::microseconds UserTime;
60 uint64_t PeakMemory = 0; ///< Maximum resident set size in KiB.
63 /// Find the first executable file \p Name in \p Paths.
65 /// This does not perform hashing as a shell would but instead stats each PATH
66 /// entry individually so should generally be avoided. Core LLVM library
67 /// functions and options should instead require fully specified paths.
69 /// \param Name name of the executable to find. If it contains any system
70 /// slashes, it will be returned as is.
71 /// \param Paths optional list of paths to search for \p Name. If empty it
72 /// will use the system PATH environment instead.
74 /// \returns The fully qualified path to the first \p Name in \p Paths if it
75 /// exists. \p Name if \p Name has slashes in it. Otherwise an error.
77 findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {});
79 // These functions change the specified standard stream (stdin or stdout) to
80 // binary mode. They return errc::success if the specified stream
81 // was changed. Otherwise a platform dependent error is returned.
82 std::error_code ChangeStdinToBinary();
83 std::error_code ChangeStdoutToBinary();
85 /// This function executes the program using the arguments provided. The
86 /// invoked program will inherit the stdin, stdout, and stderr file
87 /// descriptors, the environment and other configuration settings of the
89 /// This function waits for the program to finish, so should be avoided in
90 /// library functions that aren't expected to block. Consider using
91 /// ExecuteNoWait() instead.
92 /// \returns an integer result code indicating the status of the program.
93 /// A zero or positive value indicates the result code of the program.
94 /// -1 indicates failure to execute
95 /// -2 indicates a crash during execution or timeout
97 StringRef Program, ///< Path of the program to be executed. It is
98 ///< presumed this is the result of the findProgramByName method.
99 ArrayRef<StringRef> Args, ///< An array of strings that are passed to the
100 ///< program. The first element should be the name of the program.
101 ///< The array should **not** be terminated by an empty StringRef.
102 Optional<ArrayRef<StringRef>> Env = None, ///< An optional vector of
103 ///< strings to use for the program's environment. If not provided, the
104 ///< current program's environment will be used. If specified, the
105 ///< vector should **not** be terminated by an empty StringRef.
106 ArrayRef<Optional<StringRef>> Redirects = {}, ///<
107 ///< An array of optional paths. Should have a size of zero or three.
108 ///< If the array is empty, no redirections are performed.
109 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2)
110 ///< will be redirected to the corresponding paths, if the optional path
111 ///< is present (not \c llvm::None).
112 ///< When an empty path is passed in, the corresponding file descriptor
113 ///< will be disconnected (ie, /dev/null'd) in a portable way.
114 unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount
115 ///< of time to wait for the child process to exit. If the time
116 ///< expires, the child is killed and this call returns. If zero,
117 ///< this function will wait until the child finishes or forever if
119 unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount
120 ///< of memory can be allocated by process. If memory usage will be
121 ///< higher limit, the child is killed and this call returns. If zero
122 ///< - no memory limit.
123 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a
124 ///< string instance in which error messages will be returned. If the
125 ///< string is non-empty upon return an error occurred while invoking the
127 bool *ExecutionFailed = nullptr,
128 Optional<ProcessStatistics> *ProcStat = nullptr ///< If non-zero, provides
129 /// a pointer to a structure in which process execution statistics will be
133 /// Similar to ExecuteAndWait, but returns immediately.
134 /// @returns The \see ProcessInfo of the newly launched process.
135 /// \note On Microsoft Windows systems, users will need to either call
136 /// \see Wait until the process finished execution or win32 CloseHandle() API
137 /// on ProcessInfo.ProcessHandle to avoid memory leaks.
138 ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef<StringRef> Args,
139 Optional<ArrayRef<StringRef>> Env,
140 ArrayRef<Optional<StringRef>> Redirects = {},
141 unsigned MemoryLimit = 0,
142 std::string *ErrMsg = nullptr,
143 bool *ExecutionFailed = nullptr);
145 /// Return true if the given arguments fit within system-specific
146 /// argument length limits.
147 bool commandLineFitsWithinSystemLimits(StringRef Program,
148 ArrayRef<StringRef> Args);
150 /// Return true if the given arguments fit within system-specific
151 /// argument length limits.
152 bool commandLineFitsWithinSystemLimits(StringRef Program,
153 ArrayRef<const char *> Args);
155 /// File encoding options when writing contents that a non-UTF8 tool will
156 /// read (on Windows systems). For UNIX, we always use UTF-8.
157 enum WindowsEncodingMethod {
158 /// UTF-8 is the LLVM native encoding, being the same as "do not perform
159 /// encoding conversion".
165 /// Saves the UTF8-encoded \p contents string into the file \p FileName
166 /// using a specific encoding.
168 /// This write file function adds the possibility to choose which encoding
169 /// to use when writing a text file. On Windows, this is important when
170 /// writing files with internationalization support with an encoding that is
171 /// different from the one used in LLVM (UTF-8). We use this when writing
172 /// response files, since GCC tools on MinGW only understand legacy code
173 /// pages, and VisualStudio tools only understand UTF-16.
174 /// For UNIX, using different encodings is silently ignored, since all tools
175 /// work well with UTF-8.
176 /// This function assumes that you only use UTF-8 *text* data and will convert
177 /// it to your desired encoding before writing to the file.
179 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in
180 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is
181 /// our best shot to make gcc/ld understand international characters. This
182 /// should be changed as soon as binutils fix this to support UTF16 on mingw.
184 /// \returns non-zero error_code if failed
186 writeFileWithEncoding(StringRef FileName, StringRef Contents,
187 WindowsEncodingMethod Encoding = WEM_UTF8);
189 /// This function waits for the process specified by \p PI to finish.
190 /// \returns A \see ProcessInfo struct with Pid set to:
191 /// \li The process id of the child process if the child process has changed
193 /// \li 0 if the child process has not changed state.
194 /// \note Users of this function should always check the ReturnCode member of
195 /// the \see ProcessInfo returned from this function.
197 const ProcessInfo &PI, ///< The child process that should be waited on.
198 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of
199 ///< time to wait for the child process to exit. If the time expires, the
200 ///< child is killed and this function returns. If zero, this function
201 ///< will perform a non-blocking wait on the child process.
202 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits
203 ///< until child has terminated.
204 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a
205 ///< string instance in which error messages will be returned. If the
206 ///< string is non-empty upon return an error occurred while invoking the
208 Optional<ProcessStatistics> *ProcStat = nullptr ///< If non-zero, provides
209 /// a pointer to a structure in which process execution statistics will be
213 /// Print a command argument, and optionally quote it.
214 void printArg(llvm::raw_ostream &OS, StringRef Arg, bool Quote);
217 /// Given a list of command line arguments, quote and escape them as necessary
218 /// to build a single flat command line appropriate for calling CreateProcess
221 std::string flattenWindowsCommandLine(ArrayRef<StringRef> Args);