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   SignalError(ioStatOrErrno);
63   if (ioStat_ != IostatOk && (flags_ & hasIoMsg)) {
64     ioMsg_ = SaveDefaultCharacter(msg, length, *this);
65   }
66 }
67 
68 void IoErrorHandler::SignalErrno() { SignalError(errno); }
69 
70 void IoErrorHandler::SignalEnd() { SignalError(IostatEnd); }
71 
72 void IoErrorHandler::SignalEor() { SignalError(IostatEor); }
73 
74 bool IoErrorHandler::GetIoMsg(char *buffer, std::size_t bufferLength) {
75   const char *msg{ioMsg_.get()};
76   if (!msg) {
77     msg = IostatErrorString(ioStat_);
78   }
79   if (msg) {
80     ToFortranDefaultCharacter(buffer, bufferLength, msg);
81     return true;
82   }
83 
84   char *newBuf;
85   // Following code is taken from llvm/lib/Support/Errno.cpp
86   // in LLVM v9.0.1
87 #if HAVE_STRERROR_R
88   // strerror_r is thread-safe.
89 #if defined(__GLIBC__) && defined(_GNU_SOURCE)
90   // glibc defines its own incompatible version of strerror_r
91   // which may not use the buffer supplied.
92   newBuf = ::strerror_r(ioStat_, buffer, bufferLength);
93 #else
94   return ::strerror_r(ioStat_, buffer, bufferLength) == 0;
95 #endif
96 #elif HAVE_DECL_STRERROR_S // "Windows Secure API"
97   return ::strerror_s(buffer, bufferLength, ioStat_) == 0;
98 #elif HAVE_STRERROR
99   // Copy the thread un-safe result of strerror into
100   // the buffer as fast as possible to minimize impact
101   // of collision of strerror in multiple threads.
102   newBuf = strerror(ioStat_);
103 #else
104   // Strange that this system doesn't even have strerror
105   return false;
106 #endif
107   ::strncpy(buffer, newBuf, bufferLength - 1);
108   buffer[bufferLength - 1] = '\n';
109   return true;
110 }
111 } // namespace Fortran::runtime::io
112