1 /*
2 Copyright (c) 2018-2021 Intel Corporation
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 http://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 */
16
17 #ifndef __TBB_tbb_environment_H
18 #define __TBB_tbb_environment_H
19
20 #include <cstdlib>
21 #include <cstring>
22 #include <cerrno>
23 #include <cctype>
24
25 namespace tbb {
26 namespace detail {
27 namespace r1 {
28
29 #if __TBB_WIN8UI_SUPPORT
GetBoolEnvironmentVariable(const char *)30 static inline bool GetBoolEnvironmentVariable( const char * ) {
31 return false;
32 }
33
GetIntegralEnvironmentVariable(const char *)34 static inline long GetIntegralEnvironmentVariable( const char * ) {
35 return -1;
36 }
37 #else /* __TBB_WIN8UI_SUPPORT */
38 static inline bool GetBoolEnvironmentVariable( const char * name ) {
39 if ( const char* s = std::getenv(name) ) {
40 // The result is defined as true only if the environment variable contains
41 // no characters except one '1' character and an arbitrary number of spaces
42 // (including the absence of spaces).
43 size_t index = std::strspn(s, " ");
44 if (s[index] != '1') return false;
45 index++;
46 // Memory access after incrementing is safe, since the getenv() returns a
47 // NULL terminated string, and even if the character getting by index is '1',
48 // and this character is the end of string, after incrementing we will get
49 // an index of character, that contains '\0'
50 index += std::strspn(&s[index], " ");
51 return !s[index];
52 }
53 return false;
54 }
55
56 static inline long GetIntegralEnvironmentVariable( const char * name ) {
57 if ( const char* s = std::getenv(name) ) {
58 char* end = NULL;
59 errno = 0;
60 long value = std::strtol(s, &end, 10);
61
62 // We have exceeded the range, value is negative or string is incovertable
63 if ( errno == ERANGE || value < 0 || end==s ) {
64 return -1;
65 }
66 for ( ; *end != '\0'; end++ ) {
67 if ( !std::isspace(*end) ) {
68 return -1;
69 }
70 }
71 return value;
72 }
73 return -1;
74 }
75 #endif /* __TBB_WIN8UI_SUPPORT */
76
77 } // namespace r1
78 } // namespace detail
79 } // namespace tbb
80
81 #endif // __TBB_tbb_environment_H
82