Files
clang-p2996/lldb/source/Utility/ReproducerInstrumentation.cpp
Jonas Devlieghere 950a8aa165 [lldb/Reproducers] Support new replay mode: passive replay
Support passive replay as proposed in the RFC [1] on lldb-dev and
described in more detail on the lldb website [2].

This patch extends the LLDB_RECORD macros to re-invoke the current
function with arguments deserialized from the reproducer. This relies on
the function being called in the exact same order as during replay. It
uses the same mechanism to toggle the API boundary as during recording,
which guarantees that only boundary crossing calls are replayed.

Another major change is that before this patch we could ignore the
result of an API call, because we only cared about the observable
behavior. Now we need to be able to return the replayed result to the
SWIG bindings.

We reuse a lot of the recording infrastructure, which can be a little
confusing. We kept the existing naming to limit the amount of churn, but
might revisit that in a future patch.

[1] http://lists.llvm.org/pipermail/lldb-dev/2020-April/016100.html
[2] https://lldb.llvm.org/resources/reproducers.html

Differential revision: https://reviews.llvm.org/D77602
2020-04-20 09:41:40 -07:00

222 lines
6.6 KiB
C++

//===-- ReproducerInstrumentation.cpp -------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/ReproducerInstrumentation.h"
#include "lldb/Utility/Reproducer.h"
#include <stdio.h>
#include <stdlib.h>
#include <thread>
using namespace lldb_private;
using namespace lldb_private::repro;
void *IndexToObject::GetObjectForIndexImpl(unsigned idx) {
return m_mapping.lookup(idx);
}
void IndexToObject::AddObjectForIndexImpl(unsigned idx, void *object) {
assert(idx != 0 && "Cannot add object for sentinel");
m_mapping[idx] = object;
}
std::vector<void *> IndexToObject::GetAllObjects() const {
std::vector<std::pair<unsigned, void *>> pairs;
for (auto &e : m_mapping) {
pairs.emplace_back(e.first, e.second);
}
// Sort based on index.
std::sort(pairs.begin(), pairs.end(),
[](auto &lhs, auto &rhs) { return lhs.first < rhs.first; });
std::vector<void *> objects;
objects.reserve(pairs.size());
for (auto &p : pairs) {
objects.push_back(p.second);
}
return objects;
}
template <> const uint8_t *Deserializer::Deserialize<const uint8_t *>() {
return Deserialize<uint8_t *>();
}
template <> void *Deserializer::Deserialize<void *>() {
return const_cast<void *>(Deserialize<const void *>());
}
template <> const void *Deserializer::Deserialize<const void *>() {
return nullptr;
}
template <> char *Deserializer::Deserialize<char *>() {
return const_cast<char *>(Deserialize<const char *>());
}
template <> const char *Deserializer::Deserialize<const char *>() {
const size_t size = Deserialize<size_t>();
if (size == std::numeric_limits<size_t>::max())
return nullptr;
assert(HasData(size + 1));
const char *str = m_buffer.data();
m_buffer = m_buffer.drop_front(size + 1);
#ifdef LLDB_REPRO_INSTR_TRACE
llvm::errs() << "Deserializing with " << LLVM_PRETTY_FUNCTION << " -> \""
<< str << "\"\n";
#endif
return str;
}
template <> const char **Deserializer::Deserialize<const char **>() {
const size_t size = Deserialize<size_t>();
if (size == 0)
return nullptr;
const char **r =
reinterpret_cast<const char **>(calloc(size + 1, sizeof(char *)));
for (size_t i = 0; i < size; ++i)
r[i] = Deserialize<const char *>();
return r;
}
bool Registry::Replay(const FileSpec &file) {
auto error_or_file = llvm::MemoryBuffer::getFile(file.GetPath());
if (auto err = error_or_file.getError())
return false;
return Replay((*error_or_file)->getBuffer());
}
bool Registry::Replay(llvm::StringRef buffer) {
Deserializer deserializer(buffer);
return Replay(deserializer);
}
bool Registry::Replay(Deserializer &deserializer) {
#ifndef LLDB_REPRO_INSTR_TRACE
Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_API);
#endif
// Disable buffering stdout so that we approximate the way things get flushed
// during an interactive session.
setvbuf(stdout, nullptr, _IONBF, 0);
while (deserializer.HasData(1)) {
unsigned id = deserializer.Deserialize<unsigned>();
#ifndef LLDB_REPRO_INSTR_TRACE
LLDB_LOG(log, "Replaying {0}: {1}", id, GetSignature(id));
#else
llvm::errs() << "Replaying " << id << ": " << GetSignature(id) << "\n";
#endif
GetReplayer(id)->operator()(deserializer);
}
// Add a small artificial delay to ensure that all asynchronous events have
// completed before we exit.
std::this_thread::sleep_for(std::chrono::milliseconds(100));
return true;
}
void Registry::DoRegister(uintptr_t RunID, std::unique_ptr<Replayer> replayer,
SignatureStr signature) {
const unsigned id = m_replayers.size() + 1;
assert(m_replayers.find(RunID) == m_replayers.end());
m_replayers[RunID] = std::make_pair(std::move(replayer), id);
m_ids[id] =
std::make_pair(m_replayers[RunID].first.get(), std::move(signature));
}
unsigned Registry::GetID(uintptr_t addr) {
unsigned id = m_replayers[addr].second;
assert(id != 0 && "Forgot to add function to registry?");
return id;
}
std::string Registry::GetSignature(unsigned id) {
assert(m_ids.count(id) != 0 && "ID not in registry");
return m_ids[id].second.ToString();
}
void Registry::CheckID(unsigned expected, unsigned actual) {
if (expected != actual) {
llvm::errs() << "Reproducer expected signature " << expected << ": '"
<< GetSignature(expected) << "'\n";
llvm::errs() << "Reproducer actual signature " << actual << ": '"
<< GetSignature(actual) << "'\n";
llvm::report_fatal_error(
"Detected reproducer replay divergence. Refusing to continue.");
}
#ifdef LLDB_REPRO_INSTR_TRACE
llvm::errs() << "Replaying " << actual << ": " << GetSignature(actual)
<< "\n";
#endif
}
Replayer *Registry::GetReplayer(unsigned id) {
assert(m_ids.count(id) != 0 && "ID not in registry");
return m_ids[id].first;
}
std::string Registry::SignatureStr::ToString() const {
return (result + (result.empty() ? "" : " ") + scope + "::" + name + args)
.str();
}
unsigned ObjectToIndex::GetIndexForObjectImpl(const void *object) {
unsigned index = m_mapping.size() + 1;
auto it = m_mapping.find(object);
if (it == m_mapping.end())
m_mapping[object] = index;
return m_mapping[object];
}
Recorder::Recorder(llvm::StringRef pretty_func, std::string &&pretty_args)
: m_serializer(nullptr), m_pretty_func(pretty_func),
m_pretty_args(pretty_args), m_local_boundary(false),
m_result_recorded(true) {
if (!g_global_boundary) {
g_global_boundary = true;
m_local_boundary = true;
LLDB_LOG(GetLogIfAllCategoriesSet(LIBLLDB_LOG_API), "{0} ({1})",
m_pretty_func, m_pretty_args);
}
}
Recorder::~Recorder() {
assert(m_result_recorded && "Did you forget LLDB_RECORD_RESULT?");
UpdateBoundary();
}
void InstrumentationData::Initialize(Serializer &serializer,
Registry &registry) {
InstanceImpl().emplace(serializer, registry);
}
void InstrumentationData::Initialize(Deserializer &deserializer,
Registry &registry) {
InstanceImpl().emplace(deserializer, registry);
}
InstrumentationData &InstrumentationData::Instance() {
if (!InstanceImpl())
InstanceImpl().emplace();
return *InstanceImpl();
}
llvm::Optional<InstrumentationData> &InstrumentationData::InstanceImpl() {
static llvm::Optional<InstrumentationData> g_instrumentation_data;
return g_instrumentation_data;
}
bool lldb_private::repro::Recorder::g_global_boundary;