LLDB  mainline
Lua.cpp
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1 //===-- Lua.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 "Lua.h"
10 #include "lldb/Host/FileSystem.h"
11 #include "lldb/Utility/FileSpec.h"
12 #include "llvm/Support/Error.h"
13 #include "llvm/Support/FormatVariadic.h"
14 
15 using namespace lldb_private;
16 using namespace lldb;
17 
18 #pragma clang diagnostic push
19 #pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
20 
21 // Disable warning C4190: 'LLDBSwigPythonBreakpointCallbackFunction' has
22 // C-linkage specified, but returns UDT 'llvm::Expected<bool>' which is
23 // incompatible with C
24 #if _MSC_VER
25 #pragma warning (push)
26 #pragma warning (disable : 4190)
27 #endif
28 
29 extern "C" llvm::Expected<bool> LLDBSwigLuaBreakpointCallbackFunction(
30  lua_State *L, lldb::StackFrameSP stop_frame_sp,
31  lldb::BreakpointLocationSP bp_loc_sp, StructuredDataImpl *extra_args_impl);
32 
33 extern "C" llvm::Expected<bool> LLDBSwigLuaWatchpointCallbackFunction(
34  lua_State *L, lldb::StackFrameSP stop_frame_sp, lldb::WatchpointSP wp_sp);
35 
36 #if _MSC_VER
37 #pragma warning (pop)
38 #endif
39 
40 #pragma clang diagnostic pop
41 
42 static int lldb_print(lua_State *L) {
43  int n = lua_gettop(L);
44  lua_getglobal(L, "io");
45  lua_getfield(L, -1, "stdout");
46  lua_getfield(L, -1, "write");
47  for (int i = 1; i <= n; i++) {
48  lua_pushvalue(L, -1); // write()
49  lua_pushvalue(L, -3); // io.stdout
50  luaL_tolstring(L, i, nullptr);
51  lua_pushstring(L, i != n ? "\t" : "\n");
52  lua_call(L, 3, 0);
53  }
54  return 0;
55 }
56 
57 Lua::Lua() : m_lua_state(luaL_newstate()) {
58  assert(m_lua_state);
59  luaL_openlibs(m_lua_state);
61  lua_pushcfunction(m_lua_state, lldb_print);
62  lua_setglobal(m_lua_state, "print");
63 }
64 
66  assert(m_lua_state);
67  lua_close(m_lua_state);
68 }
69 
70 llvm::Error Lua::Run(llvm::StringRef buffer) {
71  int error =
72  luaL_loadbuffer(m_lua_state, buffer.data(), buffer.size(), "buffer") ||
73  lua_pcall(m_lua_state, 0, 0, 0);
74  if (error == LUA_OK)
75  return llvm::Error::success();
76 
77  llvm::Error e = llvm::make_error<llvm::StringError>(
78  llvm::formatv("{0}\n", lua_tostring(m_lua_state, -1)),
79  llvm::inconvertibleErrorCode());
80  // Pop error message from the stack.
81  lua_pop(m_lua_state, 1);
82  return e;
83 }
84 
85 llvm::Error Lua::RegisterBreakpointCallback(void *baton, const char *body) {
86  lua_pushlightuserdata(m_lua_state, baton);
87  const char *fmt_str = "return function(frame, bp_loc, ...) {0} end";
88  std::string func_str = llvm::formatv(fmt_str, body).str();
89  if (luaL_dostring(m_lua_state, func_str.c_str()) != LUA_OK) {
90  llvm::Error e = llvm::make_error<llvm::StringError>(
91  llvm::formatv("{0}", lua_tostring(m_lua_state, -1)),
92  llvm::inconvertibleErrorCode());
93  // Pop error message from the stack.
94  lua_pop(m_lua_state, 2);
95  return e;
96  }
97  lua_settable(m_lua_state, LUA_REGISTRYINDEX);
98  return llvm::Error::success();
99 }
100 
101 llvm::Expected<bool>
102 Lua::CallBreakpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
103  lldb::BreakpointLocationSP bp_loc_sp,
104  StructuredData::ObjectSP extra_args_sp) {
105 
106  lua_pushlightuserdata(m_lua_state, baton);
107  lua_gettable(m_lua_state, LUA_REGISTRYINDEX);
108  auto *extra_args_impl = [&]() -> StructuredDataImpl * {
109  if (extra_args_sp == nullptr)
110  return nullptr;
111  auto *extra_args_impl = new StructuredDataImpl();
112  extra_args_impl->SetObjectSP(extra_args_sp);
113  return extra_args_impl;
114  }();
116  bp_loc_sp, extra_args_impl);
117 }
118 
119 llvm::Error Lua::RegisterWatchpointCallback(void *baton, const char *body) {
120  lua_pushlightuserdata(m_lua_state, baton);
121  const char *fmt_str = "return function(frame, wp, ...) {0} end";
122  std::string func_str = llvm::formatv(fmt_str, body).str();
123  if (luaL_dostring(m_lua_state, func_str.c_str()) != LUA_OK) {
124  llvm::Error e = llvm::make_error<llvm::StringError>(
125  llvm::formatv("{0}", lua_tostring(m_lua_state, -1)),
126  llvm::inconvertibleErrorCode());
127  // Pop error message from the stack.
128  lua_pop(m_lua_state, 2);
129  return e;
130  }
131  lua_settable(m_lua_state, LUA_REGISTRYINDEX);
132  return llvm::Error::success();
133 }
134 
135 llvm::Expected<bool>
136 Lua::CallWatchpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
137  lldb::WatchpointSP wp_sp) {
138 
139  lua_pushlightuserdata(m_lua_state, baton);
140  lua_gettable(m_lua_state, LUA_REGISTRYINDEX);
142  wp_sp);
143 }
144 
145 llvm::Error Lua::CheckSyntax(llvm::StringRef buffer) {
146  int error =
147  luaL_loadbuffer(m_lua_state, buffer.data(), buffer.size(), "buffer");
148  if (error == LUA_OK) {
149  // Pop buffer
150  lua_pop(m_lua_state, 1);
151  return llvm::Error::success();
152  }
153 
154  llvm::Error e = llvm::make_error<llvm::StringError>(
155  llvm::formatv("{0}\n", lua_tostring(m_lua_state, -1)),
156  llvm::inconvertibleErrorCode());
157  // Pop error message from the stack.
158  lua_pop(m_lua_state, 1);
159  return e;
160 }
161 
162 llvm::Error Lua::LoadModule(llvm::StringRef filename) {
163  FileSpec file(filename);
164  if (!FileSystem::Instance().Exists(file)) {
165  return llvm::make_error<llvm::StringError>("invalid path",
166  llvm::inconvertibleErrorCode());
167  }
168 
169  ConstString module_extension = file.GetFileNameExtension();
170  if (module_extension != ".lua") {
171  return llvm::make_error<llvm::StringError>("invalid extension",
172  llvm::inconvertibleErrorCode());
173  }
174 
175  int error = luaL_loadfile(m_lua_state, filename.data()) ||
176  lua_pcall(m_lua_state, 0, 1, 0);
177  if (error != LUA_OK) {
178  llvm::Error e = llvm::make_error<llvm::StringError>(
179  llvm::formatv("{0}\n", lua_tostring(m_lua_state, -1)),
180  llvm::inconvertibleErrorCode());
181  // Pop error message from the stack.
182  lua_pop(m_lua_state, 1);
183  return e;
184  }
185 
186  ConstString module_name = file.GetFileNameStrippingExtension();
187  lua_setglobal(m_lua_state, module_name.GetCString());
188  return llvm::Error::success();
189 }
190 
191 llvm::Error Lua::ChangeIO(FILE *out, FILE *err) {
192  assert(out != nullptr);
193  assert(err != nullptr);
194 
195  lua_getglobal(m_lua_state, "io");
196 
197  lua_getfield(m_lua_state, -1, "stdout");
198  if (luaL_Stream *s = static_cast<luaL_Stream *>(
199  luaL_testudata(m_lua_state, -1, LUA_FILEHANDLE))) {
200  s->f = out;
201  lua_pop(m_lua_state, 1);
202  } else {
203  lua_pop(m_lua_state, 2);
204  return llvm::make_error<llvm::StringError>("could not get stdout",
205  llvm::inconvertibleErrorCode());
206  }
207 
208  lua_getfield(m_lua_state, -1, "stderr");
209  if (luaL_Stream *s = static_cast<luaL_Stream *>(
210  luaL_testudata(m_lua_state, -1, LUA_FILEHANDLE))) {
211  s->f = out;
212  lua_pop(m_lua_state, 1);
213  } else {
214  lua_pop(m_lua_state, 2);
215  return llvm::make_error<llvm::StringError>("could not get stderr",
216  llvm::inconvertibleErrorCode());
217  }
218 
219  lua_pop(m_lua_state, 1);
220  return llvm::Error::success();
221 }
FileSystem.h
Lua.h
lldb_private::Lua::CallWatchpointCallback
llvm::Expected< bool > CallWatchpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp, lldb::WatchpointSP wp_sp)
Definition: Lua.cpp:136
lldb_private::FileSpec
Definition: FileSpec.h:56
error
static llvm::raw_ostream & error(Stream &strm)
Definition: CommandReturnObject.cpp:17
lldb_private::Lua::CheckSyntax
llvm::Error CheckSyntax(llvm::StringRef buffer)
Definition: Lua.cpp:145
lldb_private::Lua::CallBreakpointCallback
llvm::Expected< bool > CallBreakpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp, lldb::BreakpointLocationSP bp_loc_sp, StructuredData::ObjectSP extra_args_sp)
Definition: Lua.cpp:102
lldb_private::Lua::ChangeIO
llvm::Error ChangeIO(FILE *out, FILE *err)
Definition: Lua.cpp:191
lldb_print
static int lldb_print(lua_State *L)
Definition: Lua.cpp:42
lldb_private::StructuredData::ObjectSP
std::shared_ptr< Object > ObjectSP
Definition: StructuredData.h:59
lldb_private::Lua::~Lua
~Lua()
Definition: Lua.cpp:65
lldb_private::ConstString
Definition: ConstString.h:40
lldb_private::Lua::Run
llvm::Error Run(llvm::StringRef buffer)
Definition: Lua.cpp:70
lldb_private::StructuredDataImpl
Definition: StructuredDataImpl.h:26
string
string(SUBSTRING ${p} 10 -1 pStripped) if($
Definition: Plugins/CMakeLists.txt:40
lldb_private::Lua::RegisterBreakpointCallback
llvm::Error RegisterBreakpointCallback(void *baton, const char *body)
Definition: Lua.cpp:85
lldb_private::luaopen_lldb
int luaopen_lldb(lua_State *L)
lldb_private::Lua::m_lua_state
lua_State * m_lua_state
Definition: Lua.h:49
LLDBSwigLuaWatchpointCallbackFunction
llvm::Expected< bool > LLDBSwigLuaWatchpointCallbackFunction(lua_State *L, lldb::StackFrameSP stop_frame_sp, lldb::WatchpointSP wp_sp)
lldb_private::ConstString::GetCString
const char * GetCString() const
Get the string value as a C string.
Definition: ConstString.h:216
lldb_private::FileSystem::Instance
static FileSystem & Instance()
Definition: common/FileSystem.cpp:45
lldb_private
A class that represents a running process on the host machine.
Definition: SBCommandInterpreterRunOptions.h:16
Error
llvm::Error Error
Definition: UdtRecordCompleter.cpp:29
FileSpec.h
lldb_private::Lua::RegisterWatchpointCallback
llvm::Error RegisterWatchpointCallback(void *baton, const char *body)
Definition: Lua.cpp:119
lldb_private::Lua::LoadModule
llvm::Error LoadModule(llvm::StringRef filename)
Definition: Lua.cpp:162
lldb_private::Lua::Lua
Lua()
Definition: Lua.cpp:57
lldb
Definition: SBAddress.h:15
LLDBSwigLuaBreakpointCallbackFunction
llvm::Expected< bool > LLDBSwigLuaBreakpointCallbackFunction(lua_State *L, lldb::StackFrameSP stop_frame_sp, lldb::BreakpointLocationSP bp_loc_sp, StructuredDataImpl *extra_args_impl)
lldb_private::FileSpec::GetFileNameExtension
ConstString GetFileNameExtension() const
Extract the extension of the file.
Definition: FileSpec.cpp:384
lldb_private::FileSpec::GetFileNameStrippingExtension
ConstString GetFileNameStrippingExtension() const
Return the filename without the extension part.
Definition: FileSpec.cpp:389