1 //===-- runtime/io-error.cpp ----------------------------------------------===//
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 #include "io-error.h"
10 #include "config.h"
11 #include "tools.h"
12 #include "flang/Runtime/magic-numbers.h"
13 #include <cerrno>
14 #include <cstdarg>
15 #include <cstdio>
16 #include <cstring>
17 
18 namespace Fortran::runtime::io {
19 
20 void IoErrorHandler::SignalError(int iostatOrErrno, const char *msg, ...) {
21   if (iostatOrErrno == IostatEnd && (flags_ & hasEnd)) {
22     if (ioStat_ == IostatOk || ioStat_ < IostatEnd) {
23       ioStat_ = IostatEnd;
24     }
25   } else if (iostatOrErrno == IostatEor && (flags_ & hasEor)) {
26     if (ioStat_ == IostatOk || ioStat_ < IostatEor) {
27       ioStat_ = IostatEor; // least priority
28     }
29   } else if (iostatOrErrno != IostatOk) {
30     if (flags_ & (hasIoStat | hasErr)) {
31       if (ioStat_ <= 0) {
32         ioStat_ = iostatOrErrno; // priority over END=/EOR=
33         if (msg && (flags_ & hasIoMsg)) {
34           char buffer[256];
35           va_list ap;
36           va_start(ap, msg);
37           std::vsnprintf(buffer, sizeof buffer, msg, ap);
38           ioMsg_ = SaveDefaultCharacter(buffer, std::strlen(buffer) + 1, *this);
39           va_end(ap);
40         }
41       }
42     } else if (msg) {
43       va_list ap;
44       va_start(ap, msg);
45       CrashArgs(msg, ap);
46       va_end(ap);
47     } else if (const char *errstr{IostatErrorString(iostatOrErrno)}) {
48       Crash(errstr);
49     } else {
50       Crash("I/O error (errno=%d): %s", iostatOrErrno,
51           std::strerror(iostatOrErrno));
52     }
53   }
54 }
55 
56 void IoErrorHandler::SignalError(int iostatOrErrno) {
57   SignalError(iostatOrErrno, nullptr);
58 }
59 
60 void IoErrorHandler::Forward(
61     int ioStatOrErrno, const char *msg, std::size_t length) {
62   if (ioStat_ != IostatOk && msg && (flags_ & hasIoMsg)) {
63     ioMsg_ = SaveDefaultCharacter(msg, length, *this);
64   }
65   if (ioStatOrErrno != IostatOk && msg) {
66     SignalError(ioStatOrErrno, "%.*s", static_cast<int>(length), msg);
67   } else {
68     SignalError(ioStatOrErrno);
69   }
70 }
71 
72 void IoErrorHandler::SignalErrno() { SignalError(errno); }
73 
74 void IoErrorHandler::SignalEnd() { SignalError(IostatEnd); }
75 
76 void IoErrorHandler::SignalEor() { SignalError(IostatEor); }
77 
78 bool IoErrorHandler::GetIoMsg(char *buffer, std::size_t bufferLength) {
79   const char *msg{ioMsg_.get()};
80   if (!msg) {
81     msg = IostatErrorString(ioStat_);
82   }
83   if (msg) {
84     ToFortranDefaultCharacter(buffer, bufferLength, msg);
85     return true;
86   }
87 
88   char *newBuf;
89   // Following code is taken from llvm/lib/Support/Errno.cpp
90   // in LLVM v9.0.1
91 #if HAVE_STRERROR_R
92   // strerror_r is thread-safe.
93 #if defined(__GLIBC__) && defined(_GNU_SOURCE)
94   // glibc defines its own incompatible version of strerror_r
95   // which may not use the buffer supplied.
96   newBuf = ::strerror_r(ioStat_, buffer, bufferLength);
97 #else
98   return ::strerror_r(ioStat_, buffer, bufferLength) == 0;
99 #endif
100 #elif HAVE_DECL_STRERROR_S // "Windows Secure API"
101   return ::strerror_s(buffer, bufferLength, ioStat_) == 0;
102 #elif HAVE_STRERROR
103   // Copy the thread un-safe result of strerror into
104   // the buffer as fast as possible to minimize impact
105   // of collision of strerror in multiple threads.
106   newBuf = strerror(ioStat_);
107 #else
108   // Strange that this system doesn't even have strerror
109   return false;
110 #endif
111   ::strncpy(buffer, newBuf, bufferLength - 1);
112   buffer[bufferLength - 1] = '\n';
113   return true;
114 }
115 } // namespace Fortran::runtime::io
116