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
lldb_print(lua_State * L)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
Lua()57 Lua::Lua() : m_lua_state(luaL_newstate()) {
58 assert(m_lua_state);
59 luaL_openlibs(m_lua_state);
60 luaopen_lldb(m_lua_state);
61 lua_pushcfunction(m_lua_state, lldb_print);
62 lua_setglobal(m_lua_state, "print");
63 }
64
~Lua()65 Lua::~Lua() {
66 assert(m_lua_state);
67 lua_close(m_lua_state);
68 }
69
Run(llvm::StringRef buffer)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
RegisterBreakpointCallback(void * baton,const char * body)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>
CallBreakpointCallback(void * baton,lldb::StackFrameSP stop_frame_sp,lldb::BreakpointLocationSP bp_loc_sp,StructuredData::ObjectSP extra_args_sp)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 }();
115 return LLDBSwigLuaBreakpointCallbackFunction(m_lua_state, stop_frame_sp,
116 bp_loc_sp, extra_args_impl);
117 }
118
RegisterWatchpointCallback(void * baton,const char * body)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>
CallWatchpointCallback(void * baton,lldb::StackFrameSP stop_frame_sp,lldb::WatchpointSP wp_sp)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);
141 return LLDBSwigLuaWatchpointCallbackFunction(m_lua_state, stop_frame_sp,
142 wp_sp);
143 }
144
CheckSyntax(llvm::StringRef buffer)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
LoadModule(llvm::StringRef filename)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
ChangeIO(FILE * out,FILE * err)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 }
222