v8/tools/debug_helper/heap-constants.cc
Seth Brenith 0a31d508f1 [tools] Teach v8_debug_helper where heap spaces start in ptr-compr mode
v8_debug_helper attempts to flag known object pointers when it can
recognize them, even if the memory pointed to is not available in the
crash dump. In ptr-compr builds, the first pages of the map space,
read-only space, and old space are always at the same offsets within the
heap reservation region, so we can more easily detect known objects.

Bug: v8:9376
Change-Id: I04e0d2357143d753f575f556e94f8fd42ce9d811
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1783729
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63624}
2019-09-09 16:14:12 +00:00

53 lines
1.8 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;
}
} // namespace v8_debug_helper_internal