1 //===- llvm/Support/Program.h ------------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the llvm::sys::Program class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SUPPORT_PROGRAM_H
15 #define LLVM_SUPPORT_PROGRAM_H
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>
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 /// Find the first executable file \p Name in \p Paths.
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.
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.
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.
70 findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = {});
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();
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
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
90 StringRef Program, ///< Path of the program to be executed. It is
91 ///< presumed this is the result of the findProgramByName method.
92 const char **Args, ///< A vector of strings that are passed to the
93 ///< program. The first element should be the name of the program.
94 ///< The list *must* be terminated by a null char* entry.
95 const char **Env = nullptr, ///< An optional vector of strings to use for
96 ///< the program's environment. If not provided, the current program's
97 ///< environment will be used.
98 ArrayRef<Optional<StringRef>> Redirects = {}, ///<
99 ///< An array of optional paths. Should have a size of zero or three.
100 ///< If the array is empty, no redirections are performed.
101 ///< Otherwise, the inferior process's stdin(0), stdout(1), and stderr(2)
102 ///< will be redirected to the corresponding paths, if the optional path
103 ///< is present (not \c llvm::None).
104 ///< When an empty path is passed in, the corresponding file descriptor
105 ///< will be disconnected (ie, /dev/null'd) in a portable way.
106 unsigned SecondsToWait = 0, ///< If non-zero, this specifies the amount
107 ///< of time to wait for the child process to exit. If the time
108 ///< expires, the child is killed and this call returns. If zero,
109 ///< this function will wait until the child finishes or forever if
111 unsigned MemoryLimit = 0, ///< If non-zero, this specifies max. amount
112 ///< of memory can be allocated by process. If memory usage will be
113 ///< higher limit, the child is killed and this call returns. If zero
114 ///< - no memory limit.
115 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a
116 ///< string instance in which error messages will be returned. If the
117 ///< string is non-empty upon return an error occurred while invoking the
119 bool *ExecutionFailed = nullptr);
121 /// Similar to ExecuteAndWait, but returns immediately.
122 /// @returns The \see ProcessInfo of the newly launced process.
123 /// \note On Microsoft Windows systems, users will need to either call
124 /// \see Wait until the process finished execution or win32 CloseHandle() API
125 /// on ProcessInfo.ProcessHandle to avoid memory leaks.
126 ProcessInfo ExecuteNoWait(StringRef Program, const char **Args,
127 const char **Env = nullptr,
128 ArrayRef<Optional<StringRef>> Redirects = {},
129 unsigned MemoryLimit = 0,
130 std::string *ErrMsg = nullptr,
131 bool *ExecutionFailed = nullptr);
133 /// Return true if the given arguments fit within system-specific
134 /// argument length limits.
135 bool commandLineFitsWithinSystemLimits(StringRef Program,
136 ArrayRef<const char *> Args);
138 /// File encoding options when writing contents that a non-UTF8 tool will
139 /// read (on Windows systems). For UNIX, we always use UTF-8.
140 enum WindowsEncodingMethod {
141 /// UTF-8 is the LLVM native encoding, being the same as "do not perform
142 /// encoding conversion".
148 /// Saves the UTF8-encoded \p contents string into the file \p FileName
149 /// using a specific encoding.
151 /// This write file function adds the possibility to choose which encoding
152 /// to use when writing a text file. On Windows, this is important when
153 /// writing files with internationalization support with an encoding that is
154 /// different from the one used in LLVM (UTF-8). We use this when writing
155 /// response files, since GCC tools on MinGW only understand legacy code
156 /// pages, and VisualStudio tools only understand UTF-16.
157 /// For UNIX, using different encodings is silently ignored, since all tools
158 /// work well with UTF-8.
159 /// This function assumes that you only use UTF-8 *text* data and will convert
160 /// it to your desired encoding before writing to the file.
162 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in
163 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is
164 /// our best shot to make gcc/ld understand international characters. This
165 /// should be changed as soon as binutils fix this to support UTF16 on mingw.
167 /// \returns non-zero error_code if failed
169 writeFileWithEncoding(StringRef FileName, StringRef Contents,
170 WindowsEncodingMethod Encoding = WEM_UTF8);
172 /// This function waits for the process specified by \p PI to finish.
173 /// \returns A \see ProcessInfo struct with Pid set to:
174 /// \li The process id of the child process if the child process has changed
176 /// \li 0 if the child process has not changed state.
177 /// \note Users of this function should always check the ReturnCode member of
178 /// the \see ProcessInfo returned from this function.
180 const ProcessInfo &PI, ///< The child process that should be waited on.
181 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of
182 ///< time to wait for the child process to exit. If the time expires, the
183 ///< child is killed and this function returns. If zero, this function
184 ///< will perform a non-blocking wait on the child process.
185 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits
186 ///< until child has terminated.
187 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a
188 ///< string instance in which error messages will be returned. If the
189 ///< string is non-empty upon return an error occurred while invoking the