usage_config.cc
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1 //
2 // Copyright 2019 The Abseil Authors.
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // https://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 
17 
18 #include <iostream>
19 #include <memory>
20 
21 #include "absl/base/attributes.h"
24 #include "absl/strings/str_cat.h"
25 #include "absl/strings/strip.h"
27 
28 extern "C" {
29 
30 // Additional report of fatal usage error message before we std::exit. Error is
31 // fatal if is_fatal argument to ReportUsageError is true.
33 
34 } // extern "C"
35 
36 namespace absl {
37 namespace flags_internal {
38 
39 namespace {
40 
41 // --------------------------------------------------------------------
42 // Returns true if flags defined in the filename should be reported with
43 // -helpshort flag.
44 
45 bool ContainsHelpshortFlags(absl::string_view filename) {
46  // By default we only want flags in binary's main. We expect the main
47  // routine to reside in <program>.cc or <program>-main.cc or
48  // <program>_main.cc, where the <program> is the name of the binary.
49  auto suffix = flags_internal::Basename(filename);
50  if (!absl::ConsumePrefix(&suffix,
52  return false;
53  return absl::StartsWith(suffix, ".") || absl::StartsWith(suffix, "-main.") ||
54  absl::StartsWith(suffix, "_main.");
55 }
56 
57 // --------------------------------------------------------------------
58 // Returns true if flags defined in the filename should be reported with
59 // -helppackage flag.
60 
61 bool ContainsHelppackageFlags(absl::string_view filename) {
62  // TODO(rogeeff): implement properly when registry is available.
63  return ContainsHelpshortFlags(filename);
64 }
65 
66 // --------------------------------------------------------------------
67 // Generates program version information into supplied output.
68 
69 std::string VersionString() {
70  std::string version_str(flags_internal::ShortProgramInvocationName());
71 
72  version_str += "\n";
73 
74 #if !defined(NDEBUG)
75  version_str += "Debug build (NDEBUG not #defined)\n";
76 #endif
77 
78  return version_str;
79 }
80 
81 // --------------------------------------------------------------------
82 // Normalizes the filename specific to the build system/filesystem used.
83 
84 std::string NormalizeFilename(absl::string_view filename) {
85  // Skip any leading slashes
86  auto pos = filename.find_first_not_of("\\/");
87  if (pos == absl::string_view::npos) return "";
88 
89  filename.remove_prefix(pos);
90  return std::string(filename);
91 }
92 
93 // --------------------------------------------------------------------
94 
95 ABSL_CONST_INIT absl::Mutex custom_usage_config_guard(absl::kConstInit);
96 ABSL_CONST_INIT FlagsUsageConfig* custom_usage_config
97  GUARDED_BY(custom_usage_config_guard) = nullptr;
98 
99 } // namespace
100 
102  absl::MutexLock l(&custom_usage_config_guard);
103 
104  if (custom_usage_config) return *custom_usage_config;
105 
106  FlagsUsageConfig default_config;
107  default_config.contains_helpshort_flags = &ContainsHelpshortFlags;
108  default_config.contains_help_flags = &ContainsHelppackageFlags;
109  default_config.contains_helppackage_flags = &ContainsHelppackageFlags;
110  default_config.version_string = &VersionString;
111  default_config.normalize_filename = &NormalizeFilename;
112 
113  return default_config;
114 }
115 
116 void ReportUsageError(absl::string_view msg, bool is_fatal) {
117  std::cerr << "ERROR: " << msg << std::endl;
118 
119  if (is_fatal) {
121  }
122 }
123 
124 } // namespace flags_internal
125 
127  absl::MutexLock l(&flags_internal::custom_usage_config_guard);
128 
129  if (!usage_config.contains_helpshort_flags)
130  usage_config.contains_helpshort_flags =
131  flags_internal::ContainsHelpshortFlags;
132 
133  if (!usage_config.contains_help_flags)
134  usage_config.contains_help_flags = flags_internal::ContainsHelppackageFlags;
135 
136  if (!usage_config.contains_helppackage_flags)
137  usage_config.contains_helppackage_flags =
138  flags_internal::ContainsHelppackageFlags;
139 
140  if (!usage_config.version_string)
141  usage_config.version_string = flags_internal::VersionString;
142 
143  if (!usage_config.normalize_filename)
144  usage_config.normalize_filename = flags_internal::NormalizeFilename;
145 
146  if (flags_internal::custom_usage_config)
147  *flags_internal::custom_usage_config = usage_config;
148  else
149  flags_internal::custom_usage_config = new FlagsUsageConfig(usage_config);
150 }
151 
152 } // namespace absl
void remove_prefix(size_type n)
Definition: string_view.h:310
#define ABSL_CONST_INIT
Definition: attributes.h:605
ABSL_ATTRIBUTE_WEAK void AbslInternalReportFatalUsageError(absl::string_view)
Definition: usage_config.cc:32
static constexpr size_type npos
Definition: string_view.h:159
flags_internal::FlagKindFilter contains_help_flags
Definition: usage_config.h:81
Definition: algorithm.h:29
void SetFlagsUsageConfig(FlagsUsageConfig usage_config)
absl::string_view Basename(absl::string_view filename)
Definition: path_util.h:33
bool ConsumePrefix(absl::string_view *str, absl::string_view expected)
Definition: strip.h:44
const char * msg
Definition: mutex.cc:254
FlagsUsageConfig GetUsageConfig()
std::string ShortProgramInvocationName()
Definition: program_name.cc:36
#define ABSL_ATTRIBUTE_WEAK
Definition: attributes.h:168
flags_internal::FlagKindFilter contains_helppackage_flags
Definition: usage_config.h:89
size_type find_first_not_of(string_view s, size_type pos=0) const noexcept
Definition: string_view.cc:152
void ReportUsageError(absl::string_view msg, bool is_fatal)
bool StartsWith(absl::string_view text, absl::string_view prefix)
Definition: match.h:52
std::function< std::string()> version_string
Definition: usage_config.h:93
static ABSL_CONST_INIT std::string *program_name GUARDED_BY(program_name_guard)
flags_internal::FlagKindFilter contains_helpshort_flags
Definition: usage_config.h:73
std::function< std::string(absl::string_view)> normalize_filename
Definition: usage_config.h:104


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autogenerated on Wed Jun 19 2019 19:19:58