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