1//===-- options.h -----------------------------------------------*- C++ -*-===//
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#ifndef SCUDO_OPTIONS_H_
10#define SCUDO_OPTIONS_H_
11
12#include "atomic_helpers.h"
13#include "common.h"
14#include "memtag.h"
15
16namespace scudo {
17
18enum class OptionBit {
19 MayReturnNull,
20 FillContents0of2,
21 FillContents1of2,
22 DeallocTypeMismatch,
23 DeleteSizeMismatch,
24 TrackAllocationStacks,
25 UseOddEvenTags,
26 UseMemoryTagging,
27 AddLargeAllocationSlack,
28};
29
30struct Options {
31 u32 Val;
32
33 bool get(OptionBit Opt) const { return Val & (1U << static_cast<u32>(Opt)); }
34
35 FillContentsMode getFillContentsMode() const {
36 return static_cast<FillContentsMode>(
37 (Val >> static_cast<u32>(OptionBit::FillContents0of2)) & 3);
38 }
39};
40
41template <typename Config> bool useMemoryTagging(const Options &Options) {
42 return allocatorSupportsMemoryTagging<Config>() &&
43 Options.get(Opt: OptionBit::UseMemoryTagging);
44}
45
46struct AtomicOptions {
47 atomic_u32 Val = {};
48
49 Options load() const { return Options{.Val: atomic_load_relaxed(A: &Val)}; }
50
51 void clear(OptionBit Opt) {
52 atomic_fetch_and(A: &Val, V: ~(1U << static_cast<u32>(Opt)),
53 MO: memory_order_relaxed);
54 }
55
56 void set(OptionBit Opt) {
57 atomic_fetch_or(A: &Val, V: 1U << static_cast<u32>(Opt), MO: memory_order_relaxed);
58 }
59
60 void setFillContentsMode(FillContentsMode FillContents) {
61 u32 Opts = atomic_load_relaxed(A: &Val), NewOpts;
62 do {
63 NewOpts = Opts;
64 NewOpts &= ~(3U << static_cast<u32>(OptionBit::FillContents0of2));
65 NewOpts |= static_cast<u32>(FillContents)
66 << static_cast<u32>(OptionBit::FillContents0of2);
67 } while (!atomic_compare_exchange_strong(A: &Val, Cmp: &Opts, Xchg: NewOpts,
68 MO: memory_order_relaxed));
69 }
70};
71
72} // namespace scudo
73
74#endif // SCUDO_OPTIONS_H_
75