v8/tools/debug_helper/heap-constants.cc
Seth Brenith 534482b35b [tools] Show contents of cached external strings from crash dumps
This change adds support for the postmortem inspection library to show
the content of cached external strings if that content is available. It
also fixes a minor annoyance where strings with unavailable data would
show up as "...". Now, if fetching the very first character fails, we
omit the literal value from the output.

Bug: v8:9376
Change-Id: Id694a774c231ab3467fb59b1c149284729acfb20
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1987922
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#65961}
2020-01-23 21:33:20 +00:00

86 lines
3.0 KiB
C++

// Copyright 2019 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "heap-constants.h"
#include "src/common/globals.h"
namespace d = v8::debug_helper;
namespace v8_debug_helper_internal {
std::string FindKnownObject(uintptr_t address,
const d::HeapAddresses& heap_addresses) {
uintptr_t containing_page = address & ~i::kPageAlignmentMask;
uintptr_t offset_in_page = address & i::kPageAlignmentMask;
// If there's a match with a known page, then search only that page.
if (containing_page == heap_addresses.map_space_first_page) {
return FindKnownObjectInMapSpace(offset_in_page);
}
if (containing_page == heap_addresses.old_space_first_page) {
return FindKnownObjectInOldSpace(offset_in_page);
}
if (containing_page == heap_addresses.read_only_space_first_page) {
return FindKnownObjectInReadOnlySpace(offset_in_page);
}
// For any unknown pages, compile a list of things this object might be.
std::string result;
if (heap_addresses.map_space_first_page == 0) {
std::string sub_result = FindKnownObjectInMapSpace(offset_in_page);
if (!sub_result.empty()) {
result += "maybe " + sub_result;
}
}
if (heap_addresses.old_space_first_page == 0) {
std::string sub_result = FindKnownObjectInOldSpace(offset_in_page);
if (!sub_result.empty()) {
result = (result.empty() ? "" : result + ", ") + "maybe " + sub_result;
}
}
if (heap_addresses.read_only_space_first_page == 0) {
std::string sub_result = FindKnownObjectInReadOnlySpace(offset_in_page);
if (!sub_result.empty()) {
result = (result.empty() ? "" : result + ", ") + "maybe " + sub_result;
}
}
return result;
}
KnownInstanceType FindKnownMapInstanceTypes(
uintptr_t address, const d::HeapAddresses& heap_addresses) {
uintptr_t containing_page = address & ~i::kPageAlignmentMask;
uintptr_t offset_in_page = address & i::kPageAlignmentMask;
// If there's a match with a known page, then search only that page.
if (containing_page == heap_addresses.map_space_first_page) {
return KnownInstanceType(
FindKnownMapInstanceTypeInMapSpace(offset_in_page));
}
if (containing_page == heap_addresses.read_only_space_first_page) {
return KnownInstanceType(
FindKnownMapInstanceTypeInReadOnlySpace(offset_in_page));
}
// For any unknown pages, compile a list of things this object might be.
KnownInstanceType result;
if (heap_addresses.map_space_first_page == 0) {
int sub_result = FindKnownMapInstanceTypeInMapSpace(offset_in_page);
if (sub_result >= 0) {
result.types.push_back(static_cast<i::InstanceType>(sub_result));
}
}
if (heap_addresses.read_only_space_first_page == 0) {
int sub_result = FindKnownMapInstanceTypeInReadOnlySpace(offset_in_page);
if (sub_result >= 0) {
result.types.push_back(static_cast<i::InstanceType>(sub_result));
}
}
return result;
}
} // namespace v8_debug_helper_internal