summaryrefslogtreecommitdiff
path: root/absl/flags/usage_config.cc
blob: 2d837ec5907ccd8c24b7d2300e4e3f263c24fd4d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
//
//  Copyright 2019 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "absl/flags/usage_config.h"

#include <iostream>
#include <string>

#include "absl/base/attributes.h"
#include "absl/base/config.h"
#include "absl/base/const_init.h"
#include "absl/base/thread_annotations.h"
#include "absl/flags/internal/path_util.h"
#include "absl/flags/internal/program_name.h"
#include "absl/strings/match.h"
#include "absl/strings/string_view.h"
#include "absl/strings/strip.h"
#include "absl/synchronization/mutex.h"

extern "C" {

// Additional report of fatal usage error message before we std::exit. Error is
// fatal if is_fatal argument to ReportUsageError is true.
ABSL_ATTRIBUTE_WEAK void AbslInternalReportFatalUsageError(absl::string_view) {}

}  // extern "C"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace flags_internal {

namespace {

// --------------------------------------------------------------------
// Returns true if flags defined in the filename should be reported with
// -helpshort flag.

bool ContainsHelpshortFlags(absl::string_view filename) {
  // By default we only want flags in binary's main. We expect the main
  // routine to reside in <program>.cc or <program>-main.cc or
  // <program>_main.cc, where the <program> is the name of the binary.
  auto suffix = flags_internal::Basename(filename);
  if (!absl::ConsumePrefix(&suffix,
                           flags_internal::ShortProgramInvocationName()))
    return false;
  return absl::StartsWith(suffix, ".") || absl::StartsWith(suffix, "-main.") ||
         absl::StartsWith(suffix, "_main.");
}

// --------------------------------------------------------------------
// Returns true if flags defined in the filename should be reported with
// -helppackage flag.

bool ContainsHelppackageFlags(absl::string_view filename) {
  // TODO(rogeeff): implement properly when registry is available.
  return ContainsHelpshortFlags(filename);
}

// --------------------------------------------------------------------
// Generates program version information into supplied output.

std::string VersionString() {
  std::string version_str(flags_internal::ShortProgramInvocationName());

  version_str += "\n";

#if !defined(NDEBUG)
  version_str += "Debug build (NDEBUG not #defined)\n";
#endif

  return version_str;
}

// --------------------------------------------------------------------
// Normalizes the filename specific to the build system/filesystem used.

std::string NormalizeFilename(absl::string_view filename) {
  // Skip any leading slashes
  auto pos = filename.find_first_not_of("\\/");
  if (pos == absl::string_view::npos) return "";

  filename.remove_prefix(pos);
  return std::string(filename);
}

// --------------------------------------------------------------------

ABSL_CONST_INIT absl::Mutex custom_usage_config_guard(absl::kConstInit);
ABSL_CONST_INIT FlagsUsageConfig* custom_usage_config
    ABSL_GUARDED_BY(custom_usage_config_guard) = nullptr;

}  // namespace

FlagsUsageConfig GetUsageConfig() {
  absl::MutexLock l(&custom_usage_config_guard);

  if (custom_usage_config) return *custom_usage_config;

  FlagsUsageConfig default_config;
  default_config.contains_helpshort_flags = &ContainsHelpshortFlags;
  default_config.contains_help_flags = &ContainsHelppackageFlags;
  default_config.contains_helppackage_flags = &ContainsHelppackageFlags;
  default_config.version_string = &VersionString;
  default_config.normalize_filename = &NormalizeFilename;

  return default_config;
}

void ReportUsageError(absl::string_view msg, bool is_fatal) {
  std::cerr << "ERROR: " << msg << std::endl;

  if (is_fatal) {
    AbslInternalReportFatalUsageError(msg);
  }
}

}  // namespace flags_internal

void SetFlagsUsageConfig(FlagsUsageConfig usage_config) {
  absl::MutexLock l(&flags_internal::custom_usage_config_guard);

  if (!usage_config.contains_helpshort_flags)
    usage_config.contains_helpshort_flags =
        flags_internal::ContainsHelpshortFlags;

  if (!usage_config.contains_help_flags)
    usage_config.contains_help_flags = flags_internal::ContainsHelppackageFlags;

  if (!usage_config.contains_helppackage_flags)
    usage_config.contains_helppackage_flags =
        flags_internal::ContainsHelppackageFlags;

  if (!usage_config.version_string)
    usage_config.version_string = flags_internal::VersionString;

  if (!usage_config.normalize_filename)
    usage_config.normalize_filename = flags_internal::NormalizeFilename;

  if (flags_internal::custom_usage_config)
    *flags_internal::custom_usage_config = usage_config;
  else
    flags_internal::custom_usage_config = new FlagsUsageConfig(usage_config);
}

ABSL_NAMESPACE_END
}  // namespace absl