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
24namespace llvm {
25namespace 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.
51 int ReturnCode;
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.
69 ErrorOr<std::string>
70 findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {});
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.
127 ProcessInfo ExecuteNoWait(StringRef Program, ArrayRef<StringRef> Args,
128 Optional<ArrayRef<StringRef>> Env,
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.
136 bool commandLineFitsWithinSystemLimits(StringRef Program,
137 ArrayRef<StringRef> Args);
138
139 /// Return true if the given arguments fit within system-specific
140 /// argument length limits.
141 bool commandLineFitsWithinSystemLimits(StringRef Program,
142 ArrayRef<const char *> Args);
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.
146 enum WindowsEncodingMethod {
147 /// UTF-8 is the LLVM native encoding, being the same as "do not perform
148 /// encoding conversion".
149 WEM_UTF8,
150 WEM_CurrentCodePage,
151 WEM_UTF16
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.
185 ProcessInfo Wait(
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
210