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 llvm::StringRef(">>> "), llvm::StringRef("..> "),
44 true, debugger.GetUseColor(), 0, *this),
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
GetInterpreterInfo()151 StructuredData::DictionarySP ScriptInterpreterLua::GetInterpreterInfo() {
152 auto info = std::make_shared<StructuredData::Dictionary>();
153 info->AddStringItem("language", "lua");
154 return info;
155 }
156
ExecuteOneLine(llvm::StringRef command,CommandReturnObject * result,const ExecuteScriptOptions & options)157 bool ScriptInterpreterLua::ExecuteOneLine(llvm::StringRef command,
158 CommandReturnObject *result,
159 const ExecuteScriptOptions &options) {
160 if (command.empty()) {
161 if (result)
162 result->AppendError("empty command passed to lua\n");
163 return false;
164 }
165
166 llvm::Expected<std::unique_ptr<ScriptInterpreterIORedirect>>
167 io_redirect_or_error = ScriptInterpreterIORedirect::Create(
168 options.GetEnableIO(), m_debugger, result);
169 if (!io_redirect_or_error) {
170 if (result)
171 result->AppendErrorWithFormatv(
172 "failed to redirect I/O: {0}\n",
173 llvm::fmt_consume(io_redirect_or_error.takeError()));
174 else
175 llvm::consumeError(io_redirect_or_error.takeError());
176 return false;
177 }
178
179 ScriptInterpreterIORedirect &io_redirect = **io_redirect_or_error;
180
181 if (llvm::Error e =
182 m_lua->ChangeIO(io_redirect.GetOutputFile()->GetStream(),
183 io_redirect.GetErrorFile()->GetStream())) {
184 result->AppendErrorWithFormatv("lua failed to redirect I/O: {0}\n",
185 llvm::toString(std::move(e)));
186 return false;
187 }
188
189 if (llvm::Error e = m_lua->Run(command)) {
190 result->AppendErrorWithFormatv(
191 "lua failed attempting to evaluate '{0}': {1}\n", command,
192 llvm::toString(std::move(e)));
193 return false;
194 }
195
196 io_redirect.Flush();
197 return true;
198 }
199
ExecuteInterpreterLoop()200 void ScriptInterpreterLua::ExecuteInterpreterLoop() {
201 LLDB_SCOPED_TIMER();
202
203 // At the moment, the only time the debugger does not have an input file
204 // handle is when this is called directly from lua, in which case it is
205 // both dangerous and unnecessary (not to mention confusing) to try to embed
206 // a running interpreter loop inside the already running lua interpreter
207 // loop, so we won't do it.
208 if (!m_debugger.GetInputFile().IsValid())
209 return;
210
211 IOHandlerSP io_handler_sp(new IOHandlerLuaInterpreter(m_debugger, *this));
212 m_debugger.RunIOHandlerAsync(io_handler_sp);
213 }
214
LoadScriptingModule(const char * filename,const LoadScriptOptions & options,lldb_private::Status & error,StructuredData::ObjectSP * module_sp,FileSpec extra_search_dir)215 bool ScriptInterpreterLua::LoadScriptingModule(
216 const char *filename, const LoadScriptOptions &options,
217 lldb_private::Status &error, StructuredData::ObjectSP *module_sp,
218 FileSpec extra_search_dir) {
219
220 if (llvm::Error e = m_lua->LoadModule(filename)) {
221 error.SetErrorStringWithFormatv("lua failed to import '{0}': {1}\n",
222 filename, llvm::toString(std::move(e)));
223 return false;
224 }
225 return true;
226 }
227
Initialize()228 void ScriptInterpreterLua::Initialize() {
229 static llvm::once_flag g_once_flag;
230
231 llvm::call_once(g_once_flag, []() {
232 PluginManager::RegisterPlugin(GetPluginNameStatic(),
233 GetPluginDescriptionStatic(),
234 lldb::eScriptLanguageLua, CreateInstance);
235 });
236 }
237
Terminate()238 void ScriptInterpreterLua::Terminate() {}
239
EnterSession(user_id_t debugger_id)240 llvm::Error ScriptInterpreterLua::EnterSession(user_id_t debugger_id) {
241 if (m_session_is_active)
242 return llvm::Error::success();
243
244 const char *fmt_str =
245 "lldb.debugger = lldb.SBDebugger.FindDebuggerWithID({0}); "
246 "lldb.target = lldb.debugger:GetSelectedTarget(); "
247 "lldb.process = lldb.target:GetProcess(); "
248 "lldb.thread = lldb.process:GetSelectedThread(); "
249 "lldb.frame = lldb.thread:GetSelectedFrame()";
250 return m_lua->Run(llvm::formatv(fmt_str, debugger_id).str());
251 }
252
LeaveSession()253 llvm::Error ScriptInterpreterLua::LeaveSession() {
254 if (!m_session_is_active)
255 return llvm::Error::success();
256
257 m_session_is_active = false;
258
259 llvm::StringRef str = "lldb.debugger = nil; "
260 "lldb.target = nil; "
261 "lldb.process = nil; "
262 "lldb.thread = nil; "
263 "lldb.frame = nil";
264 return m_lua->Run(str);
265 }
266
BreakpointCallbackFunction(void * baton,StoppointCallbackContext * context,user_id_t break_id,user_id_t break_loc_id)267 bool ScriptInterpreterLua::BreakpointCallbackFunction(
268 void *baton, StoppointCallbackContext *context, user_id_t break_id,
269 user_id_t break_loc_id) {
270 assert(context);
271
272 ExecutionContext exe_ctx(context->exe_ctx_ref);
273 Target *target = exe_ctx.GetTargetPtr();
274 if (target == nullptr)
275 return true;
276
277 StackFrameSP stop_frame_sp(exe_ctx.GetFrameSP());
278 BreakpointSP breakpoint_sp = target->GetBreakpointByID(break_id);
279 BreakpointLocationSP bp_loc_sp(breakpoint_sp->FindLocationByID(break_loc_id));
280
281 Debugger &debugger = target->GetDebugger();
282 ScriptInterpreterLua *lua_interpreter = static_cast<ScriptInterpreterLua *>(
283 debugger.GetScriptInterpreter(true, eScriptLanguageLua));
284 Lua &lua = lua_interpreter->GetLua();
285
286 CommandDataLua *bp_option_data = static_cast<CommandDataLua *>(baton);
287 llvm::Expected<bool> BoolOrErr = lua.CallBreakpointCallback(
288 baton, stop_frame_sp, bp_loc_sp, bp_option_data->m_extra_args_sp);
289 if (llvm::Error E = BoolOrErr.takeError()) {
290 debugger.GetErrorStream() << toString(std::move(E));
291 return true;
292 }
293
294 return *BoolOrErr;
295 }
296
WatchpointCallbackFunction(void * baton,StoppointCallbackContext * context,user_id_t watch_id)297 bool ScriptInterpreterLua::WatchpointCallbackFunction(
298 void *baton, StoppointCallbackContext *context, user_id_t watch_id) {
299 assert(context);
300
301 ExecutionContext exe_ctx(context->exe_ctx_ref);
302 Target *target = exe_ctx.GetTargetPtr();
303 if (target == nullptr)
304 return true;
305
306 StackFrameSP stop_frame_sp(exe_ctx.GetFrameSP());
307 WatchpointSP wp_sp = target->GetWatchpointList().FindByID(watch_id);
308
309 Debugger &debugger = target->GetDebugger();
310 ScriptInterpreterLua *lua_interpreter = static_cast<ScriptInterpreterLua *>(
311 debugger.GetScriptInterpreter(true, eScriptLanguageLua));
312 Lua &lua = lua_interpreter->GetLua();
313
314 llvm::Expected<bool> BoolOrErr =
315 lua.CallWatchpointCallback(baton, stop_frame_sp, wp_sp);
316 if (llvm::Error E = BoolOrErr.takeError()) {
317 debugger.GetErrorStream() << toString(std::move(E));
318 return true;
319 }
320
321 return *BoolOrErr;
322 }
323
CollectDataForBreakpointCommandCallback(std::vector<std::reference_wrapper<BreakpointOptions>> & bp_options_vec,CommandReturnObject & result)324 void ScriptInterpreterLua::CollectDataForBreakpointCommandCallback(
325 std::vector<std::reference_wrapper<BreakpointOptions>> &bp_options_vec,
326 CommandReturnObject &result) {
327 IOHandlerSP io_handler_sp(
328 new IOHandlerLuaInterpreter(m_debugger, *this, eIOHandlerBreakpoint));
329 io_handler_sp->SetUserData(&bp_options_vec);
330 m_debugger.RunIOHandlerAsync(io_handler_sp);
331 }
332
CollectDataForWatchpointCommandCallback(WatchpointOptions * wp_options,CommandReturnObject & result)333 void ScriptInterpreterLua::CollectDataForWatchpointCommandCallback(
334 WatchpointOptions *wp_options, CommandReturnObject &result) {
335 IOHandlerSP io_handler_sp(
336 new IOHandlerLuaInterpreter(m_debugger, *this, eIOHandlerWatchpoint));
337 io_handler_sp->SetUserData(wp_options);
338 m_debugger.RunIOHandlerAsync(io_handler_sp);
339 }
340
SetBreakpointCommandCallbackFunction(BreakpointOptions & bp_options,const char * function_name,StructuredData::ObjectSP extra_args_sp)341 Status ScriptInterpreterLua::SetBreakpointCommandCallbackFunction(
342 BreakpointOptions &bp_options, const char *function_name,
343 StructuredData::ObjectSP extra_args_sp) {
344 const char *fmt_str = "return {0}(frame, bp_loc, ...)";
345 std::string oneliner = llvm::formatv(fmt_str, function_name).str();
346 return RegisterBreakpointCallback(bp_options, oneliner.c_str(),
347 extra_args_sp);
348 }
349
SetBreakpointCommandCallback(BreakpointOptions & bp_options,const char * command_body_text)350 Status ScriptInterpreterLua::SetBreakpointCommandCallback(
351 BreakpointOptions &bp_options, const char *command_body_text) {
352 return RegisterBreakpointCallback(bp_options, command_body_text, {});
353 }
354
RegisterBreakpointCallback(BreakpointOptions & bp_options,const char * command_body_text,StructuredData::ObjectSP extra_args_sp)355 Status ScriptInterpreterLua::RegisterBreakpointCallback(
356 BreakpointOptions &bp_options, const char *command_body_text,
357 StructuredData::ObjectSP extra_args_sp) {
358 Status error;
359 auto data_up = std::make_unique<CommandDataLua>(extra_args_sp);
360 error = m_lua->RegisterBreakpointCallback(data_up.get(), command_body_text);
361 if (error.Fail())
362 return error;
363 auto baton_sp =
364 std::make_shared<BreakpointOptions::CommandBaton>(std::move(data_up));
365 bp_options.SetCallback(ScriptInterpreterLua::BreakpointCallbackFunction,
366 baton_sp);
367 return error;
368 }
369
SetWatchpointCommandCallback(WatchpointOptions * wp_options,const char * command_body_text)370 void ScriptInterpreterLua::SetWatchpointCommandCallback(
371 WatchpointOptions *wp_options, const char *command_body_text) {
372 RegisterWatchpointCallback(wp_options, command_body_text, {});
373 }
374
RegisterWatchpointCallback(WatchpointOptions * wp_options,const char * command_body_text,StructuredData::ObjectSP extra_args_sp)375 Status ScriptInterpreterLua::RegisterWatchpointCallback(
376 WatchpointOptions *wp_options, const char *command_body_text,
377 StructuredData::ObjectSP extra_args_sp) {
378 Status error;
379 auto data_up = std::make_unique<WatchpointOptions::CommandData>();
380 error = m_lua->RegisterWatchpointCallback(data_up.get(), command_body_text);
381 if (error.Fail())
382 return error;
383 auto baton_sp =
384 std::make_shared<WatchpointOptions::CommandBaton>(std::move(data_up));
385 wp_options->SetCallback(ScriptInterpreterLua::WatchpointCallbackFunction,
386 baton_sp);
387 return error;
388 }
389
390 lldb::ScriptInterpreterSP
CreateInstance(Debugger & debugger)391 ScriptInterpreterLua::CreateInstance(Debugger &debugger) {
392 return std::make_shared<ScriptInterpreterLua>(debugger);
393 }
394
GetPluginDescriptionStatic()395 llvm::StringRef ScriptInterpreterLua::GetPluginDescriptionStatic() {
396 return "Lua script interpreter";
397 }
398
GetLua()399 Lua &ScriptInterpreterLua::GetLua() { return *m_lua; }
400