crashpad_info.cc | Explore in Territory

// Copyright 2014 The Crashpad Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "client/crashpad_info.h"

#include <type_traits>

#include "base/numerics/safe_conversions.h"
#include "build/build_config.h"
#include "util/misc/address_sanitizer.h"
#include "util/misc/from_pointer_cast.h"

#if BUILDFLAG(IS_APPLE)
#include <mach-o/loader.h>
#endif

namespace {

// Don’t change this when simply adding fields. Readers will size-check the
// structure and ignore fields they’re aware of when not present, as well as
// fields they’re not aware of. Only change this when introducing an
// incompatible layout, with the understanding that existing readers will not
// understand new versions.
constexpr uint32_t kCrashpadInfoVersion = …;

// Creates a `UserDataMinidumpStreamListEntry` with the given fields, and
// returns a pointer to it. The caller takes ownership of the returned object.
crashpad::internal::UserDataMinidumpStreamListEntry* CreateListEntry(
    uint64_t next,
    uint32_t stream_type,
    const void* data,
    size_t size) { … }

}  // namespace

namespace crashpad {

static_assert …;

// This structure needs to be stored somewhere that is easy to find without
// external information.
//
// It isn’t placed in an unnamed namespace: hopefully, this will catch attempts
// to place multiple copies of this structure into the same module. If that’s
// attempted, and the name of the symbol is the same in each translation unit,
// it will result in a linker error, which is better than having multiple
// structures show up.
//
// This may result in a static module initializer in debug-mode builds, but
// because it’s POD, no code should need to run to initialize this under
// release-mode optimization.

#if BUILDFLAG(IS_POSIX)
__attribute__((

#if BUILDFLAG(IS_APPLE)
    // Put the structure in a well-known section name where it can be easily
    // found without having to consult the symbol table.
    section(SEG_DATA ",crashpad_info"),
#endif

#if defined(ADDRESS_SANITIZER)
    // AddressSanitizer would add a trailing red zone of at least 32 bytes,
    // which would be reflected in the size of the custom section. This confuses
    // MachOImageReader::GetCrashpadInfo(), which finds that the section’s size
    // disagrees with the structure’s size_ field. By specifying an alignment
    // greater than the red zone size, the red zone will be suppressed.
    aligned(64),
#endif  // defined(ADDRESS_SANITIZER)

    // There's no need to expose this as a public symbol from the symbol table.
    // All accesses from the outside can locate the well-known section name.
    visibility("hidden"),

    // The “used” attribute prevents the structure from being dead-stripped.
    used))

#elif BUILDFLAG(IS_WIN)

// Put the struct in a section name CPADinfo where it can be found without the
// symbol table.
#pragma section("CPADinfo", read, write)
__declspec(allocate("CPADinfo"))

#else  // !BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_WIN)
#error Port
#endif  // !BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_WIN)

CrashpadInfo g_crashpad_info;

extern "C" int* CRASHPAD_NOTE_REFERENCE;

// static
CrashpadInfo* CrashpadInfo::GetCrashpadInfo() { … }

CrashpadInfo::CrashpadInfo()
    : … { … }

UserDataMinidumpStreamHandle* CrashpadInfo::AddUserDataMinidumpStream(
    uint32_t stream_type,
    const void* data,
    size_t size) { … }

UserDataMinidumpStreamHandle* CrashpadInfo::UpdateUserDataMinidumpStream(
    UserDataMinidumpStreamHandle* stream_to_update,
    uint32_t stream_type,
    const void* data,
    size_t size) { … }

}  // namespace crashpad
chromium/third_party/crashpad/crashpad/client/crashpad_info.cc
