Coverage Report

Created: 2024-09-23 06:29

/src/abseil-cpp/absl/base/internal/strerror.cc
Line
Count
Source (jump to first uncovered line)
1
// Copyright 2020 The Abseil Authors.
2
//
3
// Licensed under the Apache License, Version 2.0 (the "License");
4
// you may not use this file except in compliance with the License.
5
// You may obtain a copy of the License at
6
//
7
//      https://www.apache.org/licenses/LICENSE-2.0
8
//
9
// Unless required by applicable law or agreed to in writing, software
10
// distributed under the License is distributed on an "AS IS" BASIS,
11
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12
// See the License for the specific language governing permissions and
13
// limitations under the License.
14
15
#include "absl/base/internal/strerror.h"
16
17
#include <array>
18
#include <cerrno>
19
#include <cstddef>
20
#include <cstdio>
21
#include <cstring>
22
#include <string>
23
#include <type_traits>
24
25
#include "absl/base/internal/errno_saver.h"
26
27
namespace absl {
28
ABSL_NAMESPACE_BEGIN
29
namespace base_internal {
30
namespace {
31
32
0
const char* StrErrorAdaptor(int errnum, char* buf, size_t buflen) {
33
#if defined(_WIN32)
34
  int rc = strerror_s(buf, buflen, errnum);
35
  buf[buflen - 1] = '\0';  // guarantee NUL termination
36
  if (rc == 0 && strncmp(buf, "Unknown error", buflen) == 0) *buf = '\0';
37
  return buf;
38
#else
39
  // The type of `ret` is platform-specific; both of these branches must compile
40
  // either way but only one will execute on any given platform:
41
0
  auto ret = strerror_r(errnum, buf, buflen);
42
0
  if (std::is_same<decltype(ret), int>::value) {
43
    // XSI `strerror_r`; `ret` is `int`:
44
0
    if (ret) *buf = '\0';
45
0
    return buf;
46
0
  } else {
47
    // GNU `strerror_r`; `ret` is `char *`:
48
0
    return reinterpret_cast<const char*>(ret);
49
0
  }
50
0
#endif
51
0
}
52
53
0
std::string StrErrorInternal(int errnum) {
54
0
  char buf[100];
55
0
  const char* str = StrErrorAdaptor(errnum, buf, sizeof buf);
56
0
  if (*str == '\0') {
57
0
    snprintf(buf, sizeof buf, "Unknown error %d", errnum);
58
0
    str = buf;
59
0
  }
60
0
  return str;
61
0
}
62
63
// kSysNerr is the number of errors from a recent glibc. `StrError()` falls back
64
// to `StrErrorAdaptor()` if the value is larger than this.
65
constexpr int kSysNerr = 135;
66
67
0
std::array<std::string, kSysNerr>* NewStrErrorTable() {
68
0
  auto* table = new std::array<std::string, kSysNerr>;
69
0
  for (size_t i = 0; i < table->size(); ++i) {
70
0
    (*table)[i] = StrErrorInternal(static_cast<int>(i));
71
0
  }
72
0
  return table;
73
0
}
74
75
}  // namespace
76
77
0
std::string StrError(int errnum) {
78
0
  absl::base_internal::ErrnoSaver errno_saver;
79
0
  static const auto* table = NewStrErrorTable();
80
0
  if (errnum >= 0 && static_cast<size_t>(errnum) < table->size()) {
81
0
    return (*table)[static_cast<size_t>(errnum)];
82
0
  }
83
0
  return StrErrorInternal(errnum);
84
0
}
85
86
}  // namespace base_internal
87
ABSL_NAMESPACE_END
88
}  // namespace absl