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 "SWIGLuaBridge.h"
11 #include "lldb/Host/FileSystem.h"
12 #include "lldb/Utility/FileSpec.h"
13 #include "llvm/Support/Error.h"
14 #include "llvm/Support/FormatVariadic.h"
15
16 using namespace lldb_private;
17 using namespace lldb;
18
lldb_print(lua_State * L)19 static int lldb_print(lua_State *L) {
20 int n = lua_gettop(L);
21 lua_getglobal(L, "io");
22 lua_getfield(L, -1, "stdout");
23 lua_getfield(L, -1, "write");
24 for (int i = 1; i <= n; i++) {
25 lua_pushvalue(L, -1); // write()
26 lua_pushvalue(L, -3); // io.stdout
27 luaL_tolstring(L, i, nullptr);
28 lua_pushstring(L, i != n ? "\t" : "\n");
29 lua_call(L, 3, 0);
30 }
31 return 0;
32 }
33
Lua()34 Lua::Lua() : m_lua_state(luaL_newstate()) {
35 assert(m_lua_state);
36 luaL_openlibs(m_lua_state);
37 luaopen_lldb(m_lua_state);
38 lua_pushcfunction(m_lua_state, lldb_print);
39 lua_setglobal(m_lua_state, "print");
40 }
41
~Lua()42 Lua::~Lua() {
43 assert(m_lua_state);
44 lua_close(m_lua_state);
45 }
46
Run(llvm::StringRef buffer)47 llvm::Error Lua::Run(llvm::StringRef buffer) {
48 int error =
49 luaL_loadbuffer(m_lua_state, buffer.data(), buffer.size(), "buffer") ||
50 lua_pcall(m_lua_state, 0, 0, 0);
51 if (error == LUA_OK)
52 return llvm::Error::success();
53
54 llvm::Error e = llvm::make_error<llvm::StringError>(
55 llvm::formatv("{0}\n", lua_tostring(m_lua_state, -1)),
56 llvm::inconvertibleErrorCode());
57 // Pop error message from the stack.
58 lua_pop(m_lua_state, 1);
59 return e;
60 }
61
RegisterBreakpointCallback(void * baton,const char * body)62 llvm::Error Lua::RegisterBreakpointCallback(void *baton, const char *body) {
63 lua_pushlightuserdata(m_lua_state, baton);
64 const char *fmt_str = "return function(frame, bp_loc, ...) {0} end";
65 std::string func_str = llvm::formatv(fmt_str, body).str();
66 if (luaL_dostring(m_lua_state, func_str.c_str()) != LUA_OK) {
67 llvm::Error e = llvm::make_error<llvm::StringError>(
68 llvm::formatv("{0}", lua_tostring(m_lua_state, -1)),
69 llvm::inconvertibleErrorCode());
70 // Pop error message from the stack.
71 lua_pop(m_lua_state, 2);
72 return e;
73 }
74 lua_settable(m_lua_state, LUA_REGISTRYINDEX);
75 return llvm::Error::success();
76 }
77
78 llvm::Expected<bool>
CallBreakpointCallback(void * baton,lldb::StackFrameSP stop_frame_sp,lldb::BreakpointLocationSP bp_loc_sp,StructuredData::ObjectSP extra_args_sp)79 Lua::CallBreakpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
80 lldb::BreakpointLocationSP bp_loc_sp,
81 StructuredData::ObjectSP extra_args_sp) {
82
83 lua_pushlightuserdata(m_lua_state, baton);
84 lua_gettable(m_lua_state, LUA_REGISTRYINDEX);
85 StructuredDataImpl extra_args_impl(std::move(extra_args_sp));
86 return lua::SWIGBridge::LLDBSwigLuaBreakpointCallbackFunction(
87 m_lua_state, stop_frame_sp, bp_loc_sp, extra_args_impl);
88 }
89
RegisterWatchpointCallback(void * baton,const char * body)90 llvm::Error Lua::RegisterWatchpointCallback(void *baton, const char *body) {
91 lua_pushlightuserdata(m_lua_state, baton);
92 const char *fmt_str = "return function(frame, wp, ...) {0} end";
93 std::string func_str = llvm::formatv(fmt_str, body).str();
94 if (luaL_dostring(m_lua_state, func_str.c_str()) != LUA_OK) {
95 llvm::Error e = llvm::make_error<llvm::StringError>(
96 llvm::formatv("{0}", lua_tostring(m_lua_state, -1)),
97 llvm::inconvertibleErrorCode());
98 // Pop error message from the stack.
99 lua_pop(m_lua_state, 2);
100 return e;
101 }
102 lua_settable(m_lua_state, LUA_REGISTRYINDEX);
103 return llvm::Error::success();
104 }
105
106 llvm::Expected<bool>
CallWatchpointCallback(void * baton,lldb::StackFrameSP stop_frame_sp,lldb::WatchpointSP wp_sp)107 Lua::CallWatchpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
108 lldb::WatchpointSP wp_sp) {
109
110 lua_pushlightuserdata(m_lua_state, baton);
111 lua_gettable(m_lua_state, LUA_REGISTRYINDEX);
112 return lua::SWIGBridge::LLDBSwigLuaWatchpointCallbackFunction(
113 m_lua_state, stop_frame_sp, wp_sp);
114 }
115
CheckSyntax(llvm::StringRef buffer)116 llvm::Error Lua::CheckSyntax(llvm::StringRef buffer) {
117 int error =
118 luaL_loadbuffer(m_lua_state, buffer.data(), buffer.size(), "buffer");
119 if (error == LUA_OK) {
120 // Pop buffer
121 lua_pop(m_lua_state, 1);
122 return llvm::Error::success();
123 }
124
125 llvm::Error e = llvm::make_error<llvm::StringError>(
126 llvm::formatv("{0}\n", lua_tostring(m_lua_state, -1)),
127 llvm::inconvertibleErrorCode());
128 // Pop error message from the stack.
129 lua_pop(m_lua_state, 1);
130 return e;
131 }
132
LoadModule(llvm::StringRef filename)133 llvm::Error Lua::LoadModule(llvm::StringRef filename) {
134 const FileSpec file(filename);
135 if (!FileSystem::Instance().Exists(file)) {
136 return llvm::make_error<llvm::StringError>("invalid path",
137 llvm::inconvertibleErrorCode());
138 }
139
140 if (file.GetFileNameExtension() != ".lua") {
141 return llvm::make_error<llvm::StringError>("invalid extension",
142 llvm::inconvertibleErrorCode());
143 }
144
145 int error = luaL_loadfile(m_lua_state, filename.data()) ||
146 lua_pcall(m_lua_state, 0, 1, 0);
147 if (error != LUA_OK) {
148 llvm::Error e = llvm::make_error<llvm::StringError>(
149 llvm::formatv("{0}\n", lua_tostring(m_lua_state, -1)),
150 llvm::inconvertibleErrorCode());
151 // Pop error message from the stack.
152 lua_pop(m_lua_state, 1);
153 return e;
154 }
155
156 ConstString module_name = file.GetFileNameStrippingExtension();
157 lua_setglobal(m_lua_state, module_name.GetCString());
158 return llvm::Error::success();
159 }
160
ChangeIO(FILE * out,FILE * err)161 llvm::Error Lua::ChangeIO(FILE *out, FILE *err) {
162 assert(out != nullptr);
163 assert(err != nullptr);
164
165 lua_getglobal(m_lua_state, "io");
166
167 lua_getfield(m_lua_state, -1, "stdout");
168 if (luaL_Stream *s = static_cast<luaL_Stream *>(
169 luaL_testudata(m_lua_state, -1, LUA_FILEHANDLE))) {
170 s->f = out;
171 lua_pop(m_lua_state, 1);
172 } else {
173 lua_pop(m_lua_state, 2);
174 return llvm::make_error<llvm::StringError>("could not get stdout",
175 llvm::inconvertibleErrorCode());
176 }
177
178 lua_getfield(m_lua_state, -1, "stderr");
179 if (luaL_Stream *s = static_cast<luaL_Stream *>(
180 luaL_testudata(m_lua_state, -1, LUA_FILEHANDLE))) {
181 s->f = out;
182 lua_pop(m_lua_state, 1);
183 } else {
184 lua_pop(m_lua_state, 2);
185 return llvm::make_error<llvm::StringError>("could not get stderr",
186 llvm::inconvertibleErrorCode());
187 }
188
189 lua_pop(m_lua_state, 1);
190 return llvm::Error::success();
191 }
192