llvm-project/lldb/source/Interpreter/ScriptInterpreter.cpp
Med Ismail Bennani a758c9f720 [lldb/Plugins] Add memory region support in ScriptedProcess
This patch adds support for memory regions in Scripted Processes.
This is necessary to read the stack memory region in order to
reconstruct each stackframe of the program.

In order to do so, this patch makes some changes to the SBAPI, namely:
- Add a new constructor for `SBMemoryRegionInfo` that takes arguments
  such as the memory region name, address range, permissions ...
  This is used when reading memory at some address to compute the offset
  in the binary blob provided by the user.
- Add a `GetMemoryRegionContainingAddress` method to `SBMemoryRegionInfoList`
  to simplify the access to a specific memory region.

With these changes, lldb is now able to unwind the stack and reconstruct
each frame. On top of that, reloading the target module at offset 0 allows
lldb to symbolicate the `ScriptedProcess` using debug info, similarly to an
ordinary Process.

To test this, I wrote a simple program with multiple function calls, ran it in
lldb, stopped at a leaf function and read the registers values and copied
the stack memory into a binary file. These are then used in the python script.

Differential Revision: https://reviews.llvm.org/D108953

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-10-08 14:54:07 +02:00

242 lines
8.3 KiB
C++

//===-- ScriptInterpreter.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/Interpreter/ScriptInterpreter.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Host/ConnectionFileDescriptor.h"
#include "lldb/Host/Pipe.h"
#include "lldb/Host/PseudoTerminal.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Utility/Status.h"
#include "lldb/Utility/Stream.h"
#include "lldb/Utility/StringList.h"
#if defined(_WIN32)
#include "lldb/Host/windows/ConnectionGenericFileWindows.h"
#endif
#include <cstdio>
#include <cstdlib>
#include <memory>
#include <string>
using namespace lldb;
using namespace lldb_private;
ScriptInterpreter::ScriptInterpreter(
Debugger &debugger, lldb::ScriptLanguage script_lang,
lldb::ScriptedProcessInterfaceUP scripted_process_interface_up)
: m_debugger(debugger), m_script_lang(script_lang),
m_scripted_process_interface_up(
std::move(scripted_process_interface_up)) {}
void ScriptInterpreter::CollectDataForBreakpointCommandCallback(
std::vector<std::reference_wrapper<BreakpointOptions>> &bp_options_vec,
CommandReturnObject &result) {
result.AppendError(
"This script interpreter does not support breakpoint callbacks.");
}
void ScriptInterpreter::CollectDataForWatchpointCommandCallback(
WatchpointOptions *bp_options, CommandReturnObject &result) {
result.AppendError(
"This script interpreter does not support watchpoint callbacks.");
}
bool ScriptInterpreter::LoadScriptingModule(const char *filename,
const LoadScriptOptions &options,
lldb_private::Status &error,
StructuredData::ObjectSP *module_sp,
FileSpec extra_search_dir) {
error.SetErrorString(
"This script interpreter does not support importing modules.");
return false;
}
std::string ScriptInterpreter::LanguageToString(lldb::ScriptLanguage language) {
switch (language) {
case eScriptLanguageNone:
return "None";
case eScriptLanguagePython:
return "Python";
case eScriptLanguageLua:
return "Lua";
case eScriptLanguageUnknown:
return "Unknown";
}
llvm_unreachable("Unhandled ScriptInterpreter!");
}
lldb::DataExtractorSP
ScriptInterpreter::GetDataExtractorFromSBData(const lldb::SBData &data) const {
return data.m_opaque_sp;
}
Status
ScriptInterpreter::GetStatusFromSBError(const lldb::SBError &error) const {
if (error.m_opaque_up)
return *error.m_opaque_up.get();
return Status();
}
llvm::Optional<MemoryRegionInfo>
ScriptInterpreter::GetOpaqueTypeFromSBMemoryRegionInfo(
const lldb::SBMemoryRegionInfo &mem_region) const {
if (!mem_region.m_opaque_up)
return llvm::None;
return *mem_region.m_opaque_up.get();
}
lldb::ScriptLanguage
ScriptInterpreter::StringToLanguage(const llvm::StringRef &language) {
if (language.equals_insensitive(LanguageToString(eScriptLanguageNone)))
return eScriptLanguageNone;
if (language.equals_insensitive(LanguageToString(eScriptLanguagePython)))
return eScriptLanguagePython;
if (language.equals_insensitive(LanguageToString(eScriptLanguageLua)))
return eScriptLanguageLua;
return eScriptLanguageUnknown;
}
Status ScriptInterpreter::SetBreakpointCommandCallback(
std::vector<std::reference_wrapper<BreakpointOptions>> &bp_options_vec,
const char *callback_text) {
Status return_error;
for (BreakpointOptions &bp_options : bp_options_vec) {
return_error = SetBreakpointCommandCallback(bp_options, callback_text);
if (return_error.Success())
break;
}
return return_error;
}
Status ScriptInterpreter::SetBreakpointCommandCallbackFunction(
std::vector<std::reference_wrapper<BreakpointOptions>> &bp_options_vec,
const char *function_name, StructuredData::ObjectSP extra_args_sp) {
Status error;
for (BreakpointOptions &bp_options : bp_options_vec) {
error = SetBreakpointCommandCallbackFunction(bp_options, function_name,
extra_args_sp);
if (!error.Success())
return error;
}
return error;
}
std::unique_ptr<ScriptInterpreterLocker>
ScriptInterpreter::AcquireInterpreterLock() {
return std::make_unique<ScriptInterpreterLocker>();
}
static void ReadThreadBytesReceived(void *baton, const void *src,
size_t src_len) {
if (src && src_len) {
Stream *strm = (Stream *)baton;
strm->Write(src, src_len);
strm->Flush();
}
}
llvm::Expected<std::unique_ptr<ScriptInterpreterIORedirect>>
ScriptInterpreterIORedirect::Create(bool enable_io, Debugger &debugger,
CommandReturnObject *result) {
if (enable_io)
return std::unique_ptr<ScriptInterpreterIORedirect>(
new ScriptInterpreterIORedirect(debugger, result));
auto nullin = FileSystem::Instance().Open(FileSpec(FileSystem::DEV_NULL),
File::eOpenOptionReadOnly);
if (!nullin)
return nullin.takeError();
auto nullout = FileSystem::Instance().Open(FileSpec(FileSystem::DEV_NULL),
File::eOpenOptionWriteOnly);
if (!nullout)
return nullin.takeError();
return std::unique_ptr<ScriptInterpreterIORedirect>(
new ScriptInterpreterIORedirect(std::move(*nullin), std::move(*nullout)));
}
ScriptInterpreterIORedirect::ScriptInterpreterIORedirect(
std::unique_ptr<File> input, std::unique_ptr<File> output)
: m_input_file_sp(std::move(input)),
m_output_file_sp(std::make_shared<StreamFile>(std::move(output))),
m_error_file_sp(m_output_file_sp),
m_communication("lldb.ScriptInterpreterIORedirect.comm"),
m_disconnect(false) {}
ScriptInterpreterIORedirect::ScriptInterpreterIORedirect(
Debugger &debugger, CommandReturnObject *result)
: m_communication("lldb.ScriptInterpreterIORedirect.comm"),
m_disconnect(false) {
if (result) {
m_input_file_sp = debugger.GetInputFileSP();
Pipe pipe;
Status pipe_result = pipe.CreateNew(false);
#if defined(_WIN32)
lldb::file_t read_file = pipe.GetReadNativeHandle();
pipe.ReleaseReadFileDescriptor();
std::unique_ptr<ConnectionGenericFile> conn_up =
std::make_unique<ConnectionGenericFile>(read_file, true);
#else
std::unique_ptr<ConnectionFileDescriptor> conn_up =
std::make_unique<ConnectionFileDescriptor>(
pipe.ReleaseReadFileDescriptor(), true);
#endif
if (conn_up->IsConnected()) {
m_communication.SetConnection(std::move(conn_up));
m_communication.SetReadThreadBytesReceivedCallback(
ReadThreadBytesReceived, &result->GetOutputStream());
m_communication.StartReadThread();
m_disconnect = true;
FILE *outfile_handle = fdopen(pipe.ReleaseWriteFileDescriptor(), "w");
m_output_file_sp = std::make_shared<StreamFile>(outfile_handle, true);
m_error_file_sp = m_output_file_sp;
if (outfile_handle)
::setbuf(outfile_handle, nullptr);
result->SetImmediateOutputFile(debugger.GetOutputStream().GetFileSP());
result->SetImmediateErrorFile(debugger.GetErrorStream().GetFileSP());
}
}
if (!m_input_file_sp || !m_output_file_sp || !m_error_file_sp)
debugger.AdoptTopIOHandlerFilesIfInvalid(m_input_file_sp, m_output_file_sp,
m_error_file_sp);
}
void ScriptInterpreterIORedirect::Flush() {
if (m_output_file_sp)
m_output_file_sp->Flush();
if (m_error_file_sp)
m_error_file_sp->Flush();
}
ScriptInterpreterIORedirect::~ScriptInterpreterIORedirect() {
if (!m_disconnect)
return;
assert(m_output_file_sp);
assert(m_error_file_sp);
assert(m_output_file_sp == m_error_file_sp);
// Close the write end of the pipe since we are done with our one line
// script. This should cause the read thread that output_comm is using to
// exit.
m_output_file_sp->GetFile().Close();
// The close above should cause this thread to exit when it gets to the end
// of file, so let it get all its data.
m_communication.JoinReadThread();
// Now we can close the read end of the pipe.
m_communication.Disconnect();
}