1 //===-- ubsan_flags.cpp ---------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Runtime flags for UndefinedBehaviorSanitizer.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "ubsan_platform.h"
14 #if CAN_SANITIZE_UB
15 #include "ubsan_flags.h"
16 #include "sanitizer_common/sanitizer_common.h"
17 #include "sanitizer_common/sanitizer_flags.h"
18 #include "sanitizer_common/sanitizer_flag_parser.h"
19 
20 #include <stdlib.h>
21 
22 namespace __ubsan {
23 
24 static const char *GetFlag(const char *flag) {
25   // We cannot call getenv() from inside a preinit array initializer
26   if (SANITIZER_CAN_USE_PREINIT_ARRAY) {
27     return GetEnv(flag);
28   } else {
29     return getenv(flag);
30   }
31 }
32 
33 Flags ubsan_flags;
34 
35 void Flags::SetDefaults() {
36 #define UBSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
37 #include "ubsan_flags.inc"
38 #undef UBSAN_FLAG
39 }
40 
41 void RegisterUbsanFlags(FlagParser *parser, Flags *f) {
42 #define UBSAN_FLAG(Type, Name, DefaultValue, Description) \
43   RegisterFlag(parser, #Name, Description, &f->Name);
44 #include "ubsan_flags.inc"
45 #undef UBSAN_FLAG
46 }
47 
48 void InitializeFlags() {
49   SetCommonFlagsDefaults();
50   {
51     CommonFlags cf;
52     cf.CopyFrom(*common_flags());
53     cf.external_symbolizer_path = GetFlag("UBSAN_SYMBOLIZER_PATH");
54     OverrideCommonFlags(cf);
55   }
56 
57   Flags *f = flags();
58   f->SetDefaults();
59 
60   FlagParser parser;
61   RegisterCommonFlags(&parser);
62   RegisterUbsanFlags(&parser, f);
63 
64   // Override from user-specified string.
65   parser.ParseString(__ubsan_default_options());
66   // Override from environment variable.
67   parser.ParseStringFromEnv("UBSAN_OPTIONS");
68   InitializeCommonFlags();
69   if (Verbosity()) ReportUnrecognizedFlags();
70 
71   if (common_flags()->help) parser.PrintFlagDescriptions();
72 }
73 
74 }  // namespace __ubsan
75 
76 SANITIZER_INTERFACE_WEAK_DEF(const char *, __ubsan_default_options, void) {
77   return "";
78 }
79 
80 #endif  // CAN_SANITIZE_UB
81