1// Copyright 2015 Google Inc. All rights reserved.
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// http://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 "commandlineflags.h"
16
17#include <algorithm>
18#include <cctype>
19#include <cstdlib>
20#include <cstring>
21#include <iostream>
22#include <limits>
23#include <map>
24#include <utility>
25
26#include "../src/string_util.h"
27
28namespace benchmark {
29namespace {
30
31// Parses 'str' for a 32-bit signed integer. If successful, writes
32// the result to *value and returns true; otherwise leaves *value
33// unchanged and returns false.
34bool ParseInt32(const std::string& src_text, const char* str, int32_t* value) {
35 // Parses the environment variable as a decimal integer.
36 char* end = nullptr;
37 const long long_value = strtol(str, &end, 10); // NOLINT
38
39 // Has strtol() consumed all characters in the string?
40 if (*end != '\0') {
41 // No - an invalid character was encountered.
42 std::cerr << src_text << " is expected to be a 32-bit integer, "
43 << "but actually has value \"" << str << "\".\n";
44 return false;
45 }
46
47 // Is the parsed value in the range of an Int32?
48 const int32_t result = static_cast<int32_t>(long_value);
49 if (long_value == std::numeric_limits<long>::max() ||
50 long_value == std::numeric_limits<long>::min() ||
51 // The parsed value overflows as a long. (strtol() returns
52 // LONG_MAX or LONG_MIN when the input overflows.)
53 result != long_value
54 // The parsed value overflows as an Int32.
55 ) {
56 std::cerr << src_text << " is expected to be a 32-bit integer, "
57 << "but actually has value \"" << str << "\", "
58 << "which overflows.\n";
59 return false;
60 }
61
62 *value = result;
63 return true;
64}
65
66// Parses 'str' for a double. If successful, writes the result to *value and
67// returns true; otherwise leaves *value unchanged and returns false.
68bool ParseDouble(const std::string& src_text, const char* str, double* value) {
69 // Parses the environment variable as a decimal integer.
70 char* end = nullptr;
71 const double double_value = strtod(str, &end); // NOLINT
72
73 // Has strtol() consumed all characters in the string?
74 if (*end != '\0') {
75 // No - an invalid character was encountered.
76 std::cerr << src_text << " is expected to be a double, "
77 << "but actually has value \"" << str << "\".\n";
78 return false;
79 }
80
81 *value = double_value;
82 return true;
83}
84
85// Parses 'str' into KV pairs. If successful, writes the result to *value and
86// returns true; otherwise leaves *value unchanged and returns false.
87bool ParseKvPairs(const std::string& src_text, const char* str,
88 std::map<std::string, std::string>* value) {
89 std::map<std::string, std::string> kvs;
90 for (const auto& kvpair : StrSplit(str, ',')) {
91 const auto kv = StrSplit(kvpair, '=');
92 if (kv.size() != 2) {
93 std::cerr << src_text << " is expected to be a comma-separated list of "
94 << "<key>=<value> strings, but actually has value \"" << str
95 << "\".\n";
96 return false;
97 }
98 if (!kvs.emplace(kv[0], kv[1]).second) {
99 std::cerr << src_text << " is expected to contain unique keys but key \""
100 << kv[0] << "\" was repeated.\n";
101 return false;
102 }
103 }
104
105 *value = kvs;
106 return true;
107}
108
109// Returns the name of the environment variable corresponding to the
110// given flag. For example, FlagToEnvVar("foo") will return
111// "BENCHMARK_FOO" in the open-source version.
112static std::string FlagToEnvVar(const char* flag) {
113 const std::string flag_str(flag);
114
115 std::string env_var;
116 for (size_t i = 0; i != flag_str.length(); ++i)
117 env_var += static_cast<char>(::toupper(flag_str.c_str()[i]));
118
119 return env_var;
120}
121
122} // namespace
123
124bool BoolFromEnv(const char* flag, bool default_val) {
125 const std::string env_var = FlagToEnvVar(flag);
126 const char* const value_str = getenv(env_var.c_str());
127 return value_str == nullptr ? default_val : IsTruthyFlagValue(value_str);
128}
129
130int32_t Int32FromEnv(const char* flag, int32_t default_val) {
131 const std::string env_var = FlagToEnvVar(flag);
132 const char* const value_str = getenv(env_var.c_str());
133 int32_t value = default_val;
134 if (value_str == nullptr ||
135 !ParseInt32(std::string("Environment variable ") + env_var, value_str,
136 &value)) {
137 return default_val;
138 }
139 return value;
140}
141
142double DoubleFromEnv(const char* flag, double default_val) {
143 const std::string env_var = FlagToEnvVar(flag);
144 const char* const value_str = getenv(env_var.c_str());
145 double value = default_val;
146 if (value_str == nullptr ||
147 !ParseDouble(std::string("Environment variable ") + env_var, value_str,
148 &value)) {
149 return default_val;
150 }
151 return value;
152}
153
154const char* StringFromEnv(const char* flag, const char* default_val) {
155 const std::string env_var = FlagToEnvVar(flag);
156 const char* const value = getenv(env_var.c_str());
157 return value == nullptr ? default_val : value;
158}
159
160std::map<std::string, std::string> KvPairsFromEnv(
161 const char* flag, std::map<std::string, std::string> default_val) {
162 const std::string env_var = FlagToEnvVar(flag);
163 const char* const value_str = getenv(env_var.c_str());
164
165 if (value_str == nullptr) return default_val;
166
167 std::map<std::string, std::string> value;
168 if (!ParseKvPairs("Environment variable " + env_var, value_str, &value)) {
169 return default_val;
170 }
171 return value;
172}
173
174// Parses a string as a command line flag. The string should have
175// the format "--flag=value". When def_optional is true, the "=value"
176// part can be omitted.
177//
178// Returns the value of the flag, or nullptr if the parsing failed.
179const char* ParseFlagValue(const char* str, const char* flag,
180 bool def_optional) {
181 // str and flag must not be nullptr.
182 if (str == nullptr || flag == nullptr) return nullptr;
183
184 // The flag must start with "--".
185 const std::string flag_str = std::string("--") + std::string(flag);
186 const size_t flag_len = flag_str.length();
187 if (strncmp(str, flag_str.c_str(), flag_len) != 0) return nullptr;
188
189 // Skips the flag name.
190 const char* flag_end = str + flag_len;
191
192 // When def_optional is true, it's OK to not have a "=value" part.
193 if (def_optional && (flag_end[0] == '\0')) return flag_end;
194
195 // If def_optional is true and there are more characters after the
196 // flag name, or if def_optional is false, there must be a '=' after
197 // the flag name.
198 if (flag_end[0] != '=') return nullptr;
199
200 // Returns the string after "=".
201 return flag_end + 1;
202}
203
204bool ParseBoolFlag(const char* str, const char* flag, bool* value) {
205 // Gets the value of the flag as a string.
206 const char* const value_str = ParseFlagValue(str, flag, true);
207
208 // Aborts if the parsing failed.
209 if (value_str == nullptr) return false;
210
211 // Converts the string value to a bool.
212 *value = IsTruthyFlagValue(value_str);
213 return true;
214}
215
216bool ParseInt32Flag(const char* str, const char* flag, int32_t* value) {
217 // Gets the value of the flag as a string.
218 const char* const value_str = ParseFlagValue(str, flag, false);
219
220 // Aborts if the parsing failed.
221 if (value_str == nullptr) return false;
222
223 // Sets *value to the value of the flag.
224 return ParseInt32(std::string("The value of flag --") + flag, value_str,
225 value);
226}
227
228bool ParseDoubleFlag(const char* str, const char* flag, double* value) {
229 // Gets the value of the flag as a string.
230 const char* const value_str = ParseFlagValue(str, flag, false);
231
232 // Aborts if the parsing failed.
233 if (value_str == nullptr) return false;
234
235 // Sets *value to the value of the flag.
236 return ParseDouble(std::string("The value of flag --") + flag, value_str,
237 value);
238}
239
240bool ParseStringFlag(const char* str, const char* flag, std::string* value) {
241 // Gets the value of the flag as a string.
242 const char* const value_str = ParseFlagValue(str, flag, false);
243
244 // Aborts if the parsing failed.
245 if (value_str == nullptr) return false;
246
247 *value = value_str;
248 return true;
249}
250
251bool ParseKeyValueFlag(const char* str, const char* flag,
252 std::map<std::string, std::string>* value) {
253 const char* const value_str = ParseFlagValue(str, flag, false);
254
255 if (value_str == nullptr) return false;
256
257 for (const auto& kvpair : StrSplit(value_str, ',')) {
258 const auto kv = StrSplit(kvpair, '=');
259 if (kv.size() != 2) return false;
260 value->emplace(kv[0], kv[1]);
261 }
262
263 return true;
264}
265
266bool IsFlag(const char* str, const char* flag) {
267 return (ParseFlagValue(str, flag, true) != nullptr);
268}
269
270bool IsTruthyFlagValue(const std::string& value) {
271 if (value.size() == 1) {
272 char v = value[0];
273 return isalnum(v) &&
274 !(v == '0' || v == 'f' || v == 'F' || v == 'n' || v == 'N');
275 } else if (!value.empty()) {
276 std::string value_lower(value);
277 std::transform(value_lower.begin(), value_lower.end(), value_lower.begin(),
278 [](char c) { return static_cast<char>(::tolower(c)); });
279 return !(value_lower == "false" || value_lower == "no" ||
280 value_lower == "off");
281 } else
282 return true;
283}
284
285} // end namespace benchmark
286