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/Support/ErrorOr.h"
19 #include "llvm/Support/Path.h"
20 #include <system_error>
25 /// This is the OS-specific separator for PATH like environment variables:
26 // a colon on Unix or a semicolon on Windows.
27 #if defined(LLVM_ON_UNIX)
28 const char EnvPathSeparator = ':';
29 #elif defined (LLVM_ON_WIN32)
30 const char EnvPathSeparator = ';';
33 /// @brief This struct encapsulates information about a process.
35 #if defined(LLVM_ON_UNIX)
36 typedef pid_t ProcessId;
37 #elif defined(LLVM_ON_WIN32)
38 typedef unsigned long ProcessId; // Must match the type of DWORD on Windows.
39 typedef void * HANDLE; // Must match the type of HANDLE on Windows.
40 /// The handle to the process (available on Windows only).
43 #error "ProcessInfo is not defined for this platform!"
46 /// The process identifier.
49 /// The return code, set after execution.
55 /// This function attempts to locate a program in the operating
56 /// system's file system using some pre-determined set of locations to search
57 /// (e.g. the PATH on Unix). Paths with slashes are returned unmodified.
59 /// It does not perform hashing as a shell would but instead stats each PATH
60 /// entry individually so should generally be avoided. Core LLVM library
61 /// functions and options should instead require fully specified paths.
63 /// @returns A string containing the path of the program or an empty string if
64 /// the program could not be found.
65 std::string FindProgramByName(const std::string& name);
67 /// \brief Find the first executable file \p Name in \p Paths.
69 /// This does not perform hashing as a shell would but instead stats each PATH
70 /// entry individually so should generally be avoided. Core LLVM library
71 /// functions and options should instead require fully specified paths.
73 /// \param Name name of the executable to find. If it contains any system
74 /// slashes, it will be returned as is.
75 /// \param Paths optional list of paths to search for \p Name. If empty it
76 /// will use the system PATH environment instead.
78 /// \returns The fully qualified path to the first \p Name in \p Paths if it
79 /// exists. \p Name if \p Name has slashes in it. Otherwise an error.
81 findProgramByName(StringRef Name,
82 ArrayRef<StringRef> Paths = ArrayRef<StringRef>());
84 // These functions change the specified standard stream (stdin or stdout) to
85 // binary mode. They return errc::success if the specified stream
86 // was changed. Otherwise a platform dependent error is returned.
87 std::error_code ChangeStdinToBinary();
88 std::error_code ChangeStdoutToBinary();
90 /// This function executes the program using the arguments provided. The
91 /// invoked program will inherit the stdin, stdout, and stderr file
92 /// descriptors, the environment and other configuration settings of the
94 /// This function waits for the program to finish, so should be avoided in
95 /// library functions that aren't expected to block. Consider using
96 /// ExecuteNoWait() instead.
97 /// @returns an integer result code indicating the status of the program.
98 /// A zero or positive value indicates the result code of the program.
99 /// -1 indicates failure to execute
100 /// -2 indicates a crash during execution or timeout
102 StringRef Program, ///< Path of the program to be executed. It is
103 /// presumed this is the result of the FindProgramByName method.
104 const char **args, ///< A vector of strings that are passed to the
105 ///< program. The first element should be the name of the program.
106 ///< The list *must* be terminated by a null char* entry.
107 const char **env = nullptr, ///< An optional vector of strings to use for
108 ///< the program's environment. If not provided, the current program's
109 ///< environment will be used.
110 const StringRef **redirects = nullptr, ///< An optional array of pointers
111 ///< to paths. If the array is null, no redirection is done. The array
112 ///< should have a size of at least three. The inferior process's
113 ///< stdin(0), stdout(1), and stderr(2) will be redirected to the
114 ///< corresponding paths.
115 ///< When an empty path is passed in, the corresponding file
116 ///< descriptor will be disconnected (ie, /dev/null'd) in a portable
118 unsigned secondsToWait = 0, ///< If non-zero, this specifies the amount
119 ///< of time to wait for the child process to exit. If the time
120 ///< expires, the child is killed and this call returns. If zero,
121 ///< this function will wait until the child finishes or forever if
123 unsigned memoryLimit = 0, ///< If non-zero, this specifies max. amount
124 ///< of memory can be allocated by process. If memory usage will be
125 ///< higher limit, the child is killed and this call returns. If zero
126 ///< - no memory limit.
127 std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a
128 ///< string instance in which error messages will be returned. If the
129 ///< string is non-empty upon return an error occurred while invoking the
131 bool *ExecutionFailed = nullptr);
133 /// Similar to ExecuteAndWait, but returns immediately.
134 /// @returns The \see ProcessInfo of the newly launced process.
135 /// \note On Microsoft Windows systems, users will need to either call \see
136 /// Wait until the process finished execution or win32 CloseHandle() API on
137 /// ProcessInfo.ProcessHandle to avoid memory leaks.
139 ExecuteNoWait(StringRef Program, const char **args, const char **env = nullptr,
140 const StringRef **redirects = nullptr, unsigned memoryLimit = 0,
141 std::string *ErrMsg = nullptr, bool *ExecutionFailed = nullptr);
143 /// Return true if the given arguments fit within system-specific
144 /// argument length limits.
145 bool argumentsFitWithinSystemLimits(ArrayRef<const char*> Args);
147 /// File encoding options when writing contents that a non-UTF8 tool will
148 /// read (on Windows systems). For UNIX, we always use UTF-8.
149 enum WindowsEncodingMethod {
150 /// UTF-8 is the LLVM native encoding, being the same as "do not perform
151 /// encoding conversion".
157 /// Saves the UTF8-encoded \p contents string into the file \p FileName
158 /// using a specific encoding.
160 /// This write file function adds the possibility to choose which encoding
161 /// to use when writing a text file. On Windows, this is important when
162 /// writing files with internationalization support with an encoding that is
163 /// different from the one used in LLVM (UTF-8). We use this when writing
164 /// response files, since GCC tools on MinGW only understand legacy code
165 /// pages, and VisualStudio tools only understand UTF-16.
166 /// For UNIX, using different encodings is silently ignored, since all tools
167 /// work well with UTF-8.
168 /// This function assumes that you only use UTF-8 *text* data and will convert
169 /// it to your desired encoding before writing to the file.
171 /// FIXME: We use EM_CurrentCodePage to write response files for GNU tools in
172 /// a MinGW/MinGW-w64 environment, which has serious flaws but currently is
173 /// our best shot to make gcc/ld understand international characters. This
174 /// should be changed as soon as binutils fix this to support UTF16 on mingw.
176 /// \returns non-zero error_code if failed
178 writeFileWithEncoding(StringRef FileName, StringRef Contents,
179 WindowsEncodingMethod Encoding = WEM_UTF8);
181 /// This function waits for the process specified by \p PI to finish.
182 /// \returns A \see ProcessInfo struct with Pid set to:
183 /// \li The process id of the child process if the child process has changed
185 /// \li 0 if the child process has not changed state.
186 /// \note Users of this function should always check the ReturnCode member of
187 /// the \see ProcessInfo returned from this function.
189 const ProcessInfo &PI, ///< The child process that should be waited on.
190 unsigned SecondsToWait, ///< If non-zero, this specifies the amount of
191 ///< time to wait for the child process to exit. If the time expires, the
192 ///< child is killed and this function returns. If zero, this function
193 ///< will perform a non-blocking wait on the child process.
194 bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits
195 ///< until child has terminated.
196 std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a
197 ///< string instance in which error messages will be returned. If the
198 ///< string is non-empty upon return an error occurred while invoking the