//===------------------------ tysan_platform.h ----------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of TypeSanitizer.
//
// Platform specific information for TySan.
//===----------------------------------------------------------------------===//

#ifndef TYSAN_PLATFORM_H
#define TYSAN_PLATFORM_H

namespace __tysan {

#if defined(__x86_64__) || SANITIZER_APPLE
struct Mapping {
  static const uptr kShadowAddr = 0x010000000000ull;
  static const uptr kAppAddr = 0x550000000000ull;
  static const uptr kAppMemMsk = ~0x780000000000ull;
  static const uptr kPtrShift = 3;
};
#elif defined(__aarch64__)
struct Mapping39 {
  static const uptr kShadowAddr = 0x0800000000ull;
  static const uptr kAppAddr = 0x5500000000ull;
  static const uptr kAppMemMsk = ~0x7800000000ull;
  static const uptr kPtrShift = 3;
};

struct Mapping42 {
  static const uptr kShadowAddr = 0x10000000000ull;
  static const uptr kAppAddr = 0x2aa00000000ull;
  static const uptr kAppMemMsk = ~0x3c000000000ull;
  static const uptr kPtrShift = 3;
};

struct Mapping48 {
  static const uptr kShadowAddr = 0x0002000000000ull;
  static const uptr kAppAddr = 0x0aaaa00000000ull;
  static const uptr kAppMemMsk = ~0x0fff800000000ull;
  static const uptr kPtrShift = 3;
};
#define TYSAN_RUNTIME_VMA 1
#elif defined(__s390x__)
struct Mapping {
  static const uptr kShadowAddr = 0x080000000000ULL;
  static const uptr kAppAddr = 0x460000000000ULL;
  static const uptr kAppMemMsk = ~0xC00000000000ULL;
  static const uptr kPtrShift = 3;
};
#elif defined(__hexagon__)
// Hexagon is a 32-bit architecture. Each shadow entry is a 4-byte pointer
// (PtrShift=2). The shadow occupies 4x the masked app memory range.
// With a 28-bit mask (256MB of app addresses), the shadow is 1GB at
// 0x80000000-0xBFFFFFFF. App addresses that differ only in bits 28-31
// will alias in the shadow; in practice this means code/heap (low addresses)
// and stack (~0x40000000) may share shadow entries, which can cause
// false positives in rare cases.
struct Mapping {
  static const uptr kShadowAddr = 0x80000000u;
  static const uptr kAppAddr = 0xC0000000u;
  static const uptr kAppMemMsk = ~0xF0000000u;
  static const uptr kPtrShift = 2;
};
#else
#error "TySan not supported for this platform!"
#endif

#if TYSAN_RUNTIME_VMA
extern int vmaSize;
#endif

enum MappingType {
  MAPPING_SHADOW_ADDR,
  MAPPING_APP_ADDR,
  MAPPING_APP_MASK,
  MAPPING_PTR_SHIFT
};

template <typename Mapping, int Type> uptr MappingImpl(void) {
  switch (Type) {
  case MAPPING_SHADOW_ADDR:
    return Mapping::kShadowAddr;
  case MAPPING_APP_ADDR:
    return Mapping::kAppAddr;
  case MAPPING_APP_MASK:
    return Mapping::kAppMemMsk;
  case MAPPING_PTR_SHIFT:
    return Mapping::kPtrShift;
  }
}

template <int Type> uptr MappingArchImpl(void) {
#if defined(__aarch64__) && !SANITIZER_APPLE
  switch (vmaSize) {
  case 39:
    return MappingImpl<Mapping39, Type>();
  case 42:
    return MappingImpl<Mapping42, Type>();
  case 48:
    return MappingImpl<Mapping48, Type>();
  }
  DCHECK(0);
  return 0;
#else
  return MappingImpl<Mapping, Type>();
#endif
}

ALWAYS_INLINE
uptr ShadowAddr() { return MappingArchImpl<MAPPING_SHADOW_ADDR>(); }

ALWAYS_INLINE
uptr AppAddr() { return MappingArchImpl<MAPPING_APP_ADDR>(); }

ALWAYS_INLINE
uptr AppMask() { return MappingArchImpl<MAPPING_APP_MASK>(); }

ALWAYS_INLINE
uptr PtrShift() { return MappingArchImpl<MAPPING_PTR_SHIFT>(); }

} // namespace __tysan

#endif
