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
22namespace __ubsan {
23
24const char *MaybeCallUbsanDefaultOptions() {
25  return (&__ubsan_default_options) ? __ubsan_default_options() : "";
26}
27
28static const char *GetFlag(const char *flag) {
29  // We cannot call getenv() from inside a preinit array initializer
30  if (SANITIZER_CAN_USE_PREINIT_ARRAY) {
31    return GetEnv(flag);
32  } else {
33    return getenv(flag);
34  }
35}
36
37Flags ubsan_flags;
38
39void Flags::SetDefaults() {
40#define UBSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
41#include "ubsan_flags.inc"
42#undef UBSAN_FLAG
43}
44
45void RegisterUbsanFlags(FlagParser *parser, Flags *f) {
46#define UBSAN_FLAG(Type, Name, DefaultValue, Description) \
47  RegisterFlag(parser, #Name, Description, &f->Name);
48#include "ubsan_flags.inc"
49#undef UBSAN_FLAG
50}
51
52void InitializeFlags() {
53  SetCommonFlagsDefaults();
54  {
55    CommonFlags cf;
56    cf.CopyFrom(*common_flags());
57    cf.external_symbolizer_path = GetFlag("UBSAN_SYMBOLIZER_PATH");
58    OverrideCommonFlags(cf);
59  }
60
61  Flags *f = flags();
62  f->SetDefaults();
63
64  FlagParser parser;
65  RegisterCommonFlags(&parser);
66  RegisterUbsanFlags(&parser, f);
67
68  // Override from user-specified string.
69  parser.ParseString(MaybeCallUbsanDefaultOptions());
70  // Override from environment variable.
71  parser.ParseStringFromEnv("UBSAN_OPTIONS");
72  InitializeCommonFlags();
73  if (Verbosity()) ReportUnrecognizedFlags();
74
75  if (common_flags()->help) parser.PrintFlagDescriptions();
76}
77
78}  // namespace __ubsan
79
80SANITIZER_INTERFACE_WEAK_DEF(const char *, __ubsan_default_options, void) {
81  return "";
82}
83
84#endif  // CAN_SANITIZE_UB
85