1 //===-- ScriptInterpreterLua.cpp ------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "ScriptInterpreterLua.h"
10 #include "Lua.h"
11 #include "lldb/Breakpoint/StoppointCallbackContext.h"
12 #include "lldb/Core/Debugger.h"
13 #include "lldb/Core/PluginManager.h"
14 #include "lldb/Core/StreamFile.h"
15 #include "lldb/Interpreter/CommandReturnObject.h"
16 #include "lldb/Target/ExecutionContext.h"
17 #include "lldb/Utility/Stream.h"
18 #include "lldb/Utility/StringList.h"
19 #include "lldb/Utility/Timer.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/Support/FormatAdapters.h"
22 #include <memory>
23 #include <vector>
24
25 using namespace lldb;
26 using namespace lldb_private;
27
28 LLDB_PLUGIN_DEFINE(ScriptInterpreterLua)
29
30 enum ActiveIOHandler {
31 eIOHandlerNone,
32 eIOHandlerBreakpoint,
33 eIOHandlerWatchpoint
34 };
35
36 class IOHandlerLuaInterpreter : public IOHandlerDelegate,
37 public IOHandlerEditline {
38 public:
IOHandlerLuaInterpreter(Debugger & debugger,ScriptInterpreterLua & script_interpreter,ActiveIOHandler active_io_handler=eIOHandlerNone)39 IOHandlerLuaInterpreter(Debugger &debugger,
40 ScriptInterpreterLua &script_interpreter,
41 ActiveIOHandler active_io_handler = eIOHandlerNone)
42 : IOHandlerEditline(debugger, IOHandler::Type::LuaInterpreter, "lua",
43 ">>> ", "..> ", true, debugger.GetUseColor(), 0,
44 *this, nullptr),
45 m_script_interpreter(script_interpreter),
46 m_active_io_handler(active_io_handler) {
47 llvm::cantFail(m_script_interpreter.GetLua().ChangeIO(
48 debugger.GetOutputFile().GetStream(),
49 debugger.GetErrorFile().GetStream()));
50 llvm::cantFail(m_script_interpreter.EnterSession(debugger.GetID()));
51 }
52
~IOHandlerLuaInterpreter()53 ~IOHandlerLuaInterpreter() override {
54 llvm::cantFail(m_script_interpreter.LeaveSession());
55 }
56
IOHandlerActivated(IOHandler & io_handler,bool interactive)57 void IOHandlerActivated(IOHandler &io_handler, bool interactive) override {
58 const char *instructions = nullptr;
59 switch (m_active_io_handler) {
60 case eIOHandlerNone:
61 break;
62 case eIOHandlerWatchpoint:
63 instructions = "Enter your Lua command(s). Type 'quit' to end.\n"
64 "The commands are compiled as the body of the following "
65 "Lua function\n"
66 "function (frame, wp) end\n";
67 SetPrompt(llvm::StringRef("..> "));
68 break;
69 case eIOHandlerBreakpoint:
70 instructions = "Enter your Lua command(s). Type 'quit' to end.\n"
71 "The commands are compiled as the body of the following "
72 "Lua function\n"
73 "function (frame, bp_loc, ...) end\n";
74 SetPrompt(llvm::StringRef("..> "));
75 break;
76 }
77 if (instructions == nullptr)
78 return;
79 if (interactive)
80 *io_handler.GetOutputStreamFileSP() << instructions;
81 }
82
IOHandlerIsInputComplete(IOHandler & io_handler,StringList & lines)83 bool IOHandlerIsInputComplete(IOHandler &io_handler,
84 StringList &lines) override {
85 size_t last = lines.GetSize() - 1;
86 if (IsQuitCommand(lines.GetStringAtIndex(last))) {
87 if (m_active_io_handler == eIOHandlerBreakpoint ||
88 m_active_io_handler == eIOHandlerWatchpoint)
89 lines.DeleteStringAtIndex(last);
90 return true;
91 }
92 StreamString str;
93 lines.Join("\n", str);
94 if (llvm::Error E =
95 m_script_interpreter.GetLua().CheckSyntax(str.GetString())) {
96 std::string error_str = toString(std::move(E));
97 // Lua always errors out to incomplete code with '<eof>'
98 return error_str.find("<eof>") == std::string::npos;
99 }
100 // The breakpoint and watchpoint handler only exits with a explicit 'quit'
101 return m_active_io_handler != eIOHandlerBreakpoint &&
102 m_active_io_handler != eIOHandlerWatchpoint;
103 }
104
IOHandlerInputComplete(IOHandler & io_handler,std::string & data)105 void IOHandlerInputComplete(IOHandler &io_handler,
106 std::string &data) override {
107 switch (m_active_io_handler) {
108 case eIOHandlerBreakpoint: {
109 auto *bp_options_vec =
110 static_cast<std::vector<std::reference_wrapper<BreakpointOptions>> *>(
111 io_handler.GetUserData());
112 for (BreakpointOptions &bp_options : *bp_options_vec) {
113 Status error = m_script_interpreter.SetBreakpointCommandCallback(
114 bp_options, data.c_str());
115 if (error.Fail())
116 *io_handler.GetErrorStreamFileSP() << error.AsCString() << '\n';
117 }
118 io_handler.SetIsDone(true);
119 } break;
120 case eIOHandlerWatchpoint: {
121 auto *wp_options =
122 static_cast<WatchpointOptions *>(io_handler.GetUserData());
123 m_script_interpreter.SetWatchpointCommandCallback(wp_options,
124 data.c_str());
125 io_handler.SetIsDone(true);
126 } break;
127 case eIOHandlerNone:
128 if (IsQuitCommand(data)) {
129 io_handler.SetIsDone(true);
130 return;
131 }
132 if (llvm::Error error = m_script_interpreter.GetLua().Run(data))
133 *io_handler.GetErrorStreamFileSP() << toString(std::move(error));
134 break;
135 }
136 }
137
138 private:
139 ScriptInterpreterLua &m_script_interpreter;
140 ActiveIOHandler m_active_io_handler;
141
IsQuitCommand(llvm::StringRef cmd)142 bool IsQuitCommand(llvm::StringRef cmd) { return cmd.rtrim() == "quit"; }
143 };
144
ScriptInterpreterLua(Debugger & debugger)145 ScriptInterpreterLua::ScriptInterpreterLua(Debugger &debugger)
146 : ScriptInterpreter(debugger, eScriptLanguageLua),
147 m_lua(std::make_unique<Lua>()) {}
148
149 ScriptInterpreterLua::~ScriptInterpreterLua() = default;
150
ExecuteOneLine(llvm::StringRef command,CommandReturnObject * result,const ExecuteScriptOptions & options)151 bool ScriptInterpreterLua::ExecuteOneLine(llvm::StringRef command,
152 CommandReturnObject *result,
153 const ExecuteScriptOptions &options) {
154 if (command.empty()) {
155 if (result)
156 result->AppendError("empty command passed to lua\n");
157 return false;
158 }
159
160 llvm::Expected<std::unique_ptr<ScriptInterpreterIORedirect>>
161 io_redirect_or_error = ScriptInterpreterIORedirect::Create(
162 options.GetEnableIO(), m_debugger, result);
163 if (!io_redirect_or_error) {
164 if (result)
165 result->AppendErrorWithFormatv(
166 "failed to redirect I/O: {0}\n",
167 llvm::fmt_consume(io_redirect_or_error.takeError()));
168 else
169 llvm::consumeError(io_redirect_or_error.takeError());
170 return false;
171 }
172
173 ScriptInterpreterIORedirect &io_redirect = **io_redirect_or_error;
174
175 if (llvm::Error e =
176 m_lua->ChangeIO(io_redirect.GetOutputFile()->GetStream(),
177 io_redirect.GetErrorFile()->GetStream())) {
178 result->AppendErrorWithFormatv("lua failed to redirect I/O: {0}\n",
179 llvm::toString(std::move(e)));
180 return false;
181 }
182
183 if (llvm::Error e = m_lua->Run(command)) {
184 result->AppendErrorWithFormatv(
185 "lua failed attempting to evaluate '{0}': {1}\n", command,
186 llvm::toString(std::move(e)));
187 return false;
188 }
189
190 io_redirect.Flush();
191 return true;
192 }
193
ExecuteInterpreterLoop()194 void ScriptInterpreterLua::ExecuteInterpreterLoop() {
195 LLDB_SCOPED_TIMER();
196
197 // At the moment, the only time the debugger does not have an input file
198 // handle is when this is called directly from lua, in which case it is
199 // both dangerous and unnecessary (not to mention confusing) to try to embed
200 // a running interpreter loop inside the already running lua interpreter
201 // loop, so we won't do it.
202 if (!m_debugger.GetInputFile().IsValid())
203 return;
204
205 IOHandlerSP io_handler_sp(new IOHandlerLuaInterpreter(m_debugger, *this));
206 m_debugger.RunIOHandlerAsync(io_handler_sp);
207 }
208
LoadScriptingModule(const char * filename,const LoadScriptOptions & options,lldb_private::Status & error,StructuredData::ObjectSP * module_sp,FileSpec extra_search_dir)209 bool ScriptInterpreterLua::LoadScriptingModule(
210 const char *filename, const LoadScriptOptions &options,
211 lldb_private::Status &error, StructuredData::ObjectSP *module_sp,
212 FileSpec extra_search_dir) {
213
214 FileSystem::Instance().Collect(filename);
215 if (llvm::Error e = m_lua->LoadModule(filename)) {
216 error.SetErrorStringWithFormatv("lua failed to import '{0}': {1}\n",
217 filename, llvm::toString(std::move(e)));
218 return false;
219 }
220 return true;
221 }
222
Initialize()223 void ScriptInterpreterLua::Initialize() {
224 static llvm::once_flag g_once_flag;
225
226 llvm::call_once(g_once_flag, []() {
227 PluginManager::RegisterPlugin(GetPluginNameStatic(),
228 GetPluginDescriptionStatic(),
229 lldb::eScriptLanguageLua, CreateInstance);
230 });
231 }
232
Terminate()233 void ScriptInterpreterLua::Terminate() {}
234
EnterSession(user_id_t debugger_id)235 llvm::Error ScriptInterpreterLua::EnterSession(user_id_t debugger_id) {
236 if (m_session_is_active)
237 return llvm::Error::success();
238
239 const char *fmt_str =
240 "lldb.debugger = lldb.SBDebugger.FindDebuggerWithID({0}); "
241 "lldb.target = lldb.debugger:GetSelectedTarget(); "
242 "lldb.process = lldb.target:GetProcess(); "
243 "lldb.thread = lldb.process:GetSelectedThread(); "
244 "lldb.frame = lldb.thread:GetSelectedFrame()";
245 return m_lua->Run(llvm::formatv(fmt_str, debugger_id).str());
246 }
247
LeaveSession()248 llvm::Error ScriptInterpreterLua::LeaveSession() {
249 if (!m_session_is_active)
250 return llvm::Error::success();
251
252 m_session_is_active = false;
253
254 llvm::StringRef str = "lldb.debugger = nil; "
255 "lldb.target = nil; "
256 "lldb.process = nil; "
257 "lldb.thread = nil; "
258 "lldb.frame = nil";
259 return m_lua->Run(str);
260 }
261
BreakpointCallbackFunction(void * baton,StoppointCallbackContext * context,user_id_t break_id,user_id_t break_loc_id)262 bool ScriptInterpreterLua::BreakpointCallbackFunction(
263 void *baton, StoppointCallbackContext *context, user_id_t break_id,
264 user_id_t break_loc_id) {
265 assert(context);
266
267 ExecutionContext exe_ctx(context->exe_ctx_ref);
268 Target *target = exe_ctx.GetTargetPtr();
269 if (target == nullptr)
270 return true;
271
272 StackFrameSP stop_frame_sp(exe_ctx.GetFrameSP());
273 BreakpointSP breakpoint_sp = target->GetBreakpointByID(break_id);
274 BreakpointLocationSP bp_loc_sp(breakpoint_sp->FindLocationByID(break_loc_id));
275
276 Debugger &debugger = target->GetDebugger();
277 ScriptInterpreterLua *lua_interpreter = static_cast<ScriptInterpreterLua *>(
278 debugger.GetScriptInterpreter(true, eScriptLanguageLua));
279 Lua &lua = lua_interpreter->GetLua();
280
281 CommandDataLua *bp_option_data = static_cast<CommandDataLua *>(baton);
282 llvm::Expected<bool> BoolOrErr = lua.CallBreakpointCallback(
283 baton, stop_frame_sp, bp_loc_sp, bp_option_data->m_extra_args_sp);
284 if (llvm::Error E = BoolOrErr.takeError()) {
285 debugger.GetErrorStream() << toString(std::move(E));
286 return true;
287 }
288
289 return *BoolOrErr;
290 }
291
WatchpointCallbackFunction(void * baton,StoppointCallbackContext * context,user_id_t watch_id)292 bool ScriptInterpreterLua::WatchpointCallbackFunction(
293 void *baton, StoppointCallbackContext *context, user_id_t watch_id) {
294 assert(context);
295
296 ExecutionContext exe_ctx(context->exe_ctx_ref);
297 Target *target = exe_ctx.GetTargetPtr();
298 if (target == nullptr)
299 return true;
300
301 StackFrameSP stop_frame_sp(exe_ctx.GetFrameSP());
302 WatchpointSP wp_sp = target->GetWatchpointList().FindByID(watch_id);
303
304 Debugger &debugger = target->GetDebugger();
305 ScriptInterpreterLua *lua_interpreter = static_cast<ScriptInterpreterLua *>(
306 debugger.GetScriptInterpreter(true, eScriptLanguageLua));
307 Lua &lua = lua_interpreter->GetLua();
308
309 llvm::Expected<bool> BoolOrErr =
310 lua.CallWatchpointCallback(baton, stop_frame_sp, wp_sp);
311 if (llvm::Error E = BoolOrErr.takeError()) {
312 debugger.GetErrorStream() << toString(std::move(E));
313 return true;
314 }
315
316 return *BoolOrErr;
317 }
318
CollectDataForBreakpointCommandCallback(std::vector<std::reference_wrapper<BreakpointOptions>> & bp_options_vec,CommandReturnObject & result)319 void ScriptInterpreterLua::CollectDataForBreakpointCommandCallback(
320 std::vector<std::reference_wrapper<BreakpointOptions>> &bp_options_vec,
321 CommandReturnObject &result) {
322 IOHandlerSP io_handler_sp(
323 new IOHandlerLuaInterpreter(m_debugger, *this, eIOHandlerBreakpoint));
324 io_handler_sp->SetUserData(&bp_options_vec);
325 m_debugger.RunIOHandlerAsync(io_handler_sp);
326 }
327
CollectDataForWatchpointCommandCallback(WatchpointOptions * wp_options,CommandReturnObject & result)328 void ScriptInterpreterLua::CollectDataForWatchpointCommandCallback(
329 WatchpointOptions *wp_options, CommandReturnObject &result) {
330 IOHandlerSP io_handler_sp(
331 new IOHandlerLuaInterpreter(m_debugger, *this, eIOHandlerWatchpoint));
332 io_handler_sp->SetUserData(wp_options);
333 m_debugger.RunIOHandlerAsync(io_handler_sp);
334 }
335
SetBreakpointCommandCallbackFunction(BreakpointOptions & bp_options,const char * function_name,StructuredData::ObjectSP extra_args_sp)336 Status ScriptInterpreterLua::SetBreakpointCommandCallbackFunction(
337 BreakpointOptions &bp_options, const char *function_name,
338 StructuredData::ObjectSP extra_args_sp) {
339 const char *fmt_str = "return {0}(frame, bp_loc, ...)";
340 std::string oneliner = llvm::formatv(fmt_str, function_name).str();
341 return RegisterBreakpointCallback(bp_options, oneliner.c_str(),
342 extra_args_sp);
343 }
344
SetBreakpointCommandCallback(BreakpointOptions & bp_options,const char * command_body_text)345 Status ScriptInterpreterLua::SetBreakpointCommandCallback(
346 BreakpointOptions &bp_options, const char *command_body_text) {
347 return RegisterBreakpointCallback(bp_options, command_body_text, {});
348 }
349
RegisterBreakpointCallback(BreakpointOptions & bp_options,const char * command_body_text,StructuredData::ObjectSP extra_args_sp)350 Status ScriptInterpreterLua::RegisterBreakpointCallback(
351 BreakpointOptions &bp_options, const char *command_body_text,
352 StructuredData::ObjectSP extra_args_sp) {
353 Status error;
354 auto data_up = std::make_unique<CommandDataLua>(extra_args_sp);
355 error = m_lua->RegisterBreakpointCallback(data_up.get(), command_body_text);
356 if (error.Fail())
357 return error;
358 auto baton_sp =
359 std::make_shared<BreakpointOptions::CommandBaton>(std::move(data_up));
360 bp_options.SetCallback(ScriptInterpreterLua::BreakpointCallbackFunction,
361 baton_sp);
362 return error;
363 }
364
SetWatchpointCommandCallback(WatchpointOptions * wp_options,const char * command_body_text)365 void ScriptInterpreterLua::SetWatchpointCommandCallback(
366 WatchpointOptions *wp_options, const char *command_body_text) {
367 RegisterWatchpointCallback(wp_options, command_body_text, {});
368 }
369
RegisterWatchpointCallback(WatchpointOptions * wp_options,const char * command_body_text,StructuredData::ObjectSP extra_args_sp)370 Status ScriptInterpreterLua::RegisterWatchpointCallback(
371 WatchpointOptions *wp_options, const char *command_body_text,
372 StructuredData::ObjectSP extra_args_sp) {
373 Status error;
374 auto data_up = std::make_unique<WatchpointOptions::CommandData>();
375 error = m_lua->RegisterWatchpointCallback(data_up.get(), command_body_text);
376 if (error.Fail())
377 return error;
378 auto baton_sp =
379 std::make_shared<WatchpointOptions::CommandBaton>(std::move(data_up));
380 wp_options->SetCallback(ScriptInterpreterLua::WatchpointCallbackFunction,
381 baton_sp);
382 return error;
383 }
384
385 lldb::ScriptInterpreterSP
CreateInstance(Debugger & debugger)386 ScriptInterpreterLua::CreateInstance(Debugger &debugger) {
387 return std::make_shared<ScriptInterpreterLua>(debugger);
388 }
389
GetPluginNameStatic()390 lldb_private::ConstString ScriptInterpreterLua::GetPluginNameStatic() {
391 static ConstString g_name("script-lua");
392 return g_name;
393 }
394
GetPluginDescriptionStatic()395 const char *ScriptInterpreterLua::GetPluginDescriptionStatic() {
396 return "Lua script interpreter";
397 }
398
GetPluginName()399 lldb_private::ConstString ScriptInterpreterLua::GetPluginName() {
400 return GetPluginNameStatic();
401 }
402
GetPluginVersion()403 uint32_t ScriptInterpreterLua::GetPluginVersion() { return 1; }
404
GetLua()405 Lua &ScriptInterpreterLua::GetLua() { return *m_lua; }
406