1 //===- llvm/Support/Unix/Unix.h - Common Unix Include File -------*- 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 defines things specific to Unix implementations.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_SUPPORT_UNIX_UNIX_H
14 #define LLVM_LIB_SUPPORT_UNIX_UNIX_H
15 
16 //===----------------------------------------------------------------------===//
17 //=== WARNING: Implementation here must contain only generic UNIX code that
18 //===          is guaranteed to work on all UNIX variants.
19 //===----------------------------------------------------------------------===//
20 
21 #include "llvm/Config/config.h"
22 #include "llvm/Support/Chrono.h"
23 #include "llvm/Support/Errno.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include <algorithm>
26 #include <assert.h>
27 #include <cerrno>
28 #include <cstdio>
29 #include <cstdlib>
30 #include <cstring>
31 #include <string>
32 #include <sys/types.h>
33 #include <sys/wait.h>
34 
35 #ifdef HAVE_UNISTD_H
36 #include <unistd.h>
37 #endif
38 
39 #ifdef HAVE_SYS_TIME_H
40 # include <sys/time.h>
41 #endif
42 #include <time.h>
43 
44 #ifdef HAVE_DLFCN_H
45 # include <dlfcn.h>
46 #endif
47 
48 #ifdef HAVE_FCNTL_H
49 # include <fcntl.h>
50 #endif
51 
52 /// This function builds an error message into \p ErrMsg using the \p prefix
53 /// string and the Unix error number given by \p errnum. If errnum is -1, the
54 /// default then the value of errno is used.
55 /// Make an error message
56 ///
57 /// If the error number can be converted to a string, it will be
58 /// separated from prefix by ": ".
59 static inline bool MakeErrMsg(
60   std::string* ErrMsg, const std::string& prefix, int errnum = -1) {
61   if (!ErrMsg)
62     return true;
63   if (errnum == -1)
64     errnum = errno;
65   *ErrMsg = prefix + ": " + llvm::sys::StrError(errnum);
66   return true;
67 }
68 
69 // Include StrError(errnum) in a fatal error message.
70 [[noreturn]] static inline void ReportErrnumFatal(const char *Msg, int errnum) {
71   std::string ErrMsg;
72   MakeErrMsg(&ErrMsg, Msg, errnum);
73   llvm::report_fatal_error(llvm::Twine(ErrMsg));
74 }
75 
76 namespace llvm {
77 namespace sys {
78 
79 /// Convert a struct timeval to a duration. Note that timeval can be used both
80 /// as a time point and a duration. Be sure to check what the input represents.
81 inline std::chrono::microseconds toDuration(const struct timeval &TV) {
82   return std::chrono::seconds(TV.tv_sec) +
83          std::chrono::microseconds(TV.tv_usec);
84 }
85 
86 /// Convert a time point to struct timespec.
87 inline struct timespec toTimeSpec(TimePoint<> TP) {
88   using namespace std::chrono;
89 
90   struct timespec RetVal;
91   RetVal.tv_sec = toTimeT(TP);
92   RetVal.tv_nsec = (TP.time_since_epoch() % seconds(1)).count();
93   return RetVal;
94 }
95 
96 /// Convert a time point to struct timeval.
97 inline struct timeval toTimeVal(TimePoint<std::chrono::microseconds> TP) {
98   using namespace std::chrono;
99 
100   struct timeval RetVal;
101   RetVal.tv_sec = toTimeT(TP);
102   RetVal.tv_usec = (TP.time_since_epoch() % seconds(1)).count();
103   return RetVal;
104 }
105 
106 } // namespace sys
107 } // namespace llvm
108 
109 #endif
110