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// Copyright (c) 2018, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/reverse_pc_lookup_cache.h"
#include "vm/isolate.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/stub_code.h"
namespace dart {
CodePtr ReversePc::FindCodeInGroup(IsolateGroup* group,
uword pc,
bool is_return_address) {
#if defined(DART_PRECOMPILED_RUNTIME)
// This can run in the middle of GC and must not allocate handles.
NoSafepointScope no_safepoint;
if (is_return_address) {
pc--;
}
// This expected number of tables is low (one per loading unit), so we go
// through them linearly. If this changes, would could sort the table list
// during deserialization and binary search for the table.
GrowableObjectArrayPtr tables = group->object_store()->instructions_tables();
intptr_t tables_length = Smi::Value(tables->untag()->length());
for (intptr_t i = 0; i < tables_length; i++) {
InstructionsTablePtr table = static_cast<InstructionsTablePtr>(
tables->untag()->data()->untag()->element(i));
CodePtr code = InstructionsTable::FindCode(table, pc);
if (code != Code::null()) {
return code;
}
}
#endif // defined(DART_PRECOMPILED_RUNTIME)
return Code::null();
}
const UntaggedCompressedStackMaps::Payload* ReversePc::FindStackMapInGroup(
IsolateGroup* group,
uword pc,
bool is_return_address,
uword* code_start,
const UntaggedCompressedStackMaps::Payload** global_table) {
#if defined(DART_PRECOMPILED_RUNTIME)
// This can run in the middle of GC and must not allocate handles.
NoSafepointScope no_safepoint;
if (is_return_address) {
pc--;
}
// This expected number of tables is low (one per loading unit), so we go
// through them linearly. If this changes, would could sort the table list
// during deserialization and binary search for the table.
GrowableObjectArrayPtr tables = group->object_store()->instructions_tables();
intptr_t tables_length = Smi::Value(tables->untag()->length());
for (intptr_t i = 0; i < tables_length; i++) {
InstructionsTablePtr table = static_cast<InstructionsTablePtr>(
tables->untag()->data()->untag()->element(i));
auto map = InstructionsTable::FindStackMap(table, pc, code_start);
if (map != nullptr) {
// Take global table from the first table.
table = static_cast<InstructionsTablePtr>(
tables->untag()->data()->untag()->element(0));
*global_table = InstructionsTable::GetCanonicalStackMap(table);
return map;
}
}
#endif // defined(DART_PRECOMPILED_RUNTIME)
*code_start = 0;
return nullptr;
}
const UntaggedCompressedStackMaps::Payload* ReversePc::FindStackMap(
IsolateGroup* group,
uword pc,
bool is_return_address,
uword* code_start,
const UntaggedCompressedStackMaps::Payload** global_table) {
ASSERT(FLAG_precompiled_mode);
NoSafepointScope no_safepoint;
auto map = FindStackMapInGroup(group, pc, is_return_address, code_start,
global_table);
if (map == nullptr) {
map = FindStackMapInGroup(Dart::vm_isolate_group(), pc, is_return_address,
code_start, global_table);
}
return map;
}
CodePtr ReversePc::FindCode(IsolateGroup* group,
uword pc,
bool is_return_address) {
ASSERT(FLAG_precompiled_mode);
NoSafepointScope no_safepoint;
auto code_descriptor = FindCodeInGroup(group, pc, is_return_address);
if (code_descriptor == Code::null()) {
code_descriptor =
FindCodeInGroup(Dart::vm_isolate_group(), pc, is_return_address);
}
return code_descriptor;
}
CodePtr ReversePc::Lookup(IsolateGroup* group,
uword pc,
bool is_return_address) {
ASSERT(FLAG_precompiled_mode);
NoSafepointScope no_safepoint;
return FindCode(group, pc, is_return_address);
}
} // namespace dart