[lldb/lua] Add scripted watchpoints for Lua

Add support for Lua scripted watchpoints, with basic tests.

Differential Revision: https://reviews.llvm.org/D105034
This commit is contained in:
Siger Yang 2021-07-04 19:38:12 -03:00 committed by Pedro Tammela
parent 3ebfeb2586
commit e81ba28313
8 changed files with 194 additions and 8 deletions

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@ -14,6 +14,12 @@ PushSBClass (lua_State* L, lldb::SBBreakpointLocation* breakpoint_location_sb)
SWIG_NewPointerObj(L, breakpoint_location_sb, SWIGTYPE_p_lldb__SBBreakpointLocation, 0);
}
void
PushSBClass (lua_State* L, lldb::SBWatchpoint* watchpoint_sb)
{
SWIG_NewPointerObj(L, watchpoint_sb, SWIGTYPE_p_lldb__SBWatchpoint, 0);
}
void
PushSBClass (lua_State* L, lldb::SBStructuredData* structured_data_sb)
{

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@ -53,5 +53,40 @@ LLDBSwigLuaBreakpointCallbackFunction
return stop;
}
// This function is called from Lua::CallWatchpointCallback
SWIGEXPORT llvm::Expected<bool>
LLDBSwigLuaWatchpointCallbackFunction
(
lua_State *L,
lldb::StackFrameSP stop_frame_sp,
lldb::WatchpointSP wp_sp
)
{
lldb::SBFrame sb_frame(stop_frame_sp);
lldb::SBWatchpoint sb_wp(wp_sp);
int nargs = 2;
// Push the Lua wrappers
PushSBClass(L, &sb_frame);
PushSBClass(L, &sb_wp);
// Call into the Lua callback passing 'sb_frame' and 'sb_wp'.
// Expects a boolean return.
if (lua_pcall(L, nargs, 1, 0) != LUA_OK) {
llvm::Error E = llvm::make_error<llvm::StringError>(
llvm::formatv("{0}\n", lua_tostring(L, -1)),
llvm::inconvertibleErrorCode());
// Pop error message from the stack.
lua_pop(L, 1);
return std::move(E);
}
// Boolean return from the callback
bool stop = lua_toboolean(L, -1);
lua_pop(L, 1);
return stop;
}
%}

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@ -30,6 +30,9 @@ extern "C" llvm::Expected<bool> LLDBSwigLuaBreakpointCallbackFunction(
lua_State *L, lldb::StackFrameSP stop_frame_sp,
lldb::BreakpointLocationSP bp_loc_sp, StructuredDataImpl *extra_args_impl);
extern "C" llvm::Expected<bool> LLDBSwigLuaWatchpointCallbackFunction(
lua_State *L, lldb::StackFrameSP stop_frame_sp, lldb::WatchpointSP wp_sp);
#if _MSC_VER
#pragma warning (pop)
#endif
@ -113,6 +116,32 @@ Lua::CallBreakpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
bp_loc_sp, extra_args_impl);
}
llvm::Error Lua::RegisterWatchpointCallback(void *baton, const char *body) {
lua_pushlightuserdata(m_lua_state, baton);
const char *fmt_str = "return function(frame, wp, ...) {0} end";
std::string func_str = llvm::formatv(fmt_str, body).str();
if (luaL_dostring(m_lua_state, func_str.c_str()) != LUA_OK) {
llvm::Error e = llvm::make_error<llvm::StringError>(
llvm::formatv("{0}", lua_tostring(m_lua_state, -1)),
llvm::inconvertibleErrorCode());
// Pop error message from the stack.
lua_pop(m_lua_state, 2);
return e;
}
lua_settable(m_lua_state, LUA_REGISTRYINDEX);
return llvm::Error::success();
}
llvm::Expected<bool>
Lua::CallWatchpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
lldb::WatchpointSP wp_sp) {
lua_pushlightuserdata(m_lua_state, baton);
lua_gettable(m_lua_state, LUA_REGISTRYINDEX);
return LLDBSwigLuaWatchpointCallbackFunction(m_lua_state, stop_frame_sp,
wp_sp);
}
llvm::Error Lua::CheckSyntax(llvm::StringRef buffer) {
int error =
luaL_loadbuffer(m_lua_state, buffer.data(), buffer.size(), "buffer");

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@ -37,6 +37,10 @@ public:
CallBreakpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
lldb::BreakpointLocationSP bp_loc_sp,
StructuredData::ObjectSP extra_args_sp);
llvm::Error RegisterWatchpointCallback(void *baton, const char *body);
llvm::Expected<bool> CallWatchpointCallback(void *baton,
lldb::StackFrameSP stop_frame_sp,
lldb::WatchpointSP wp_sp);
llvm::Error LoadModule(llvm::StringRef filename);
llvm::Error CheckSyntax(llvm::StringRef buffer);
llvm::Error ChangeIO(FILE *out, FILE *err);

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@ -58,7 +58,13 @@ public:
const char *instructions = nullptr;
switch (m_active_io_handler) {
case eIOHandlerNone:
break;
case eIOHandlerWatchpoint:
instructions = "Enter your Lua command(s). Type 'quit' to end.\n"
"The commands are compiled as the body of the following "
"Lua function\n"
"function (frame, wp) end\n";
SetPrompt(llvm::StringRef("..> "));
break;
case eIOHandlerBreakpoint:
instructions = "Enter your Lua command(s). Type 'quit' to end.\n"
@ -78,7 +84,8 @@ public:
StringList &lines) override {
size_t last = lines.GetSize() - 1;
if (IsQuitCommand(lines.GetStringAtIndex(last))) {
if (m_active_io_handler == eIOHandlerBreakpoint)
if (m_active_io_handler == eIOHandlerBreakpoint ||
m_active_io_handler == eIOHandlerWatchpoint)
lines.DeleteStringAtIndex(last);
return true;
}
@ -90,8 +97,9 @@ public:
// Lua always errors out to incomplete code with '<eof>'
return error_str.find("<eof>") == std::string::npos;
}
// The breakpoint handler only exits with a explicit 'quit'
return m_active_io_handler != eIOHandlerBreakpoint;
// The breakpoint and watchpoint handler only exits with a explicit 'quit'
return m_active_io_handler != eIOHandlerBreakpoint &&
m_active_io_handler != eIOHandlerWatchpoint;
}
void IOHandlerInputComplete(IOHandler &io_handler,
@ -109,9 +117,13 @@ public:
}
io_handler.SetIsDone(true);
} break;
case eIOHandlerWatchpoint:
case eIOHandlerWatchpoint: {
auto *wp_options =
static_cast<WatchpointOptions *>(io_handler.GetUserData());
m_script_interpreter.SetWatchpointCommandCallback(wp_options,
data.c_str());
io_handler.SetIsDone(true);
break;
} break;
case eIOHandlerNone:
if (IsQuitCommand(data)) {
io_handler.SetIsDone(true);
@ -276,6 +288,33 @@ bool ScriptInterpreterLua::BreakpointCallbackFunction(
return *BoolOrErr;
}
bool ScriptInterpreterLua::WatchpointCallbackFunction(
void *baton, StoppointCallbackContext *context, user_id_t watch_id) {
assert(context);
ExecutionContext exe_ctx(context->exe_ctx_ref);
Target *target = exe_ctx.GetTargetPtr();
if (target == nullptr)
return true;
StackFrameSP stop_frame_sp(exe_ctx.GetFrameSP());
WatchpointSP wp_sp = target->GetWatchpointList().FindByID(watch_id);
Debugger &debugger = target->GetDebugger();
ScriptInterpreterLua *lua_interpreter = static_cast<ScriptInterpreterLua *>(
debugger.GetScriptInterpreter(true, eScriptLanguageLua));
Lua &lua = lua_interpreter->GetLua();
llvm::Expected<bool> BoolOrErr =
lua.CallWatchpointCallback(baton, stop_frame_sp, wp_sp);
if (llvm::Error E = BoolOrErr.takeError()) {
debugger.GetErrorStream() << toString(std::move(E));
return true;
}
return *BoolOrErr;
}
void ScriptInterpreterLua::CollectDataForBreakpointCommandCallback(
std::vector<std::reference_wrapper<BreakpointOptions>> &bp_options_vec,
CommandReturnObject &result) {
@ -285,6 +324,14 @@ void ScriptInterpreterLua::CollectDataForBreakpointCommandCallback(
m_debugger.RunIOHandlerAsync(io_handler_sp);
}
void ScriptInterpreterLua::CollectDataForWatchpointCommandCallback(
WatchpointOptions *wp_options, CommandReturnObject &result) {
IOHandlerSP io_handler_sp(
new IOHandlerLuaInterpreter(m_debugger, *this, eIOHandlerWatchpoint));
io_handler_sp->SetUserData(wp_options);
m_debugger.RunIOHandlerAsync(io_handler_sp);
}
Status ScriptInterpreterLua::SetBreakpointCommandCallbackFunction(
BreakpointOptions &bp_options, const char *function_name,
StructuredData::ObjectSP extra_args_sp) {
@ -314,6 +361,26 @@ Status ScriptInterpreterLua::RegisterBreakpointCallback(
return error;
}
void ScriptInterpreterLua::SetWatchpointCommandCallback(
WatchpointOptions *wp_options, const char *command_body_text) {
RegisterWatchpointCallback(wp_options, command_body_text, {});
}
Status ScriptInterpreterLua::RegisterWatchpointCallback(
WatchpointOptions *wp_options, const char *command_body_text,
StructuredData::ObjectSP extra_args_sp) {
Status error;
auto data_up = std::make_unique<WatchpointOptions::CommandData>();
error = m_lua->RegisterWatchpointCallback(data_up.get(), command_body_text);
if (error.Fail())
return error;
auto baton_sp =
std::make_shared<WatchpointOptions::CommandBaton>(std::move(data_up));
wp_options->SetCallback(ScriptInterpreterLua::WatchpointCallbackFunction,
baton_sp);
return error;
}
lldb::ScriptInterpreterSP
ScriptInterpreterLua::CreateInstance(Debugger &debugger) {
return std::make_shared<ScriptInterpreterLua>(debugger);

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@ -11,6 +11,7 @@
#include <vector>
#include "lldb/Breakpoint/WatchpointOptions.h"
#include "lldb/Core/StructuredDataImpl.h"
#include "lldb/Interpreter/ScriptInterpreter.h"
#include "lldb/Utility/Status.h"
@ -63,6 +64,10 @@ public:
lldb::user_id_t break_id,
lldb::user_id_t break_loc_id);
static bool WatchpointCallbackFunction(void *baton,
StoppointCallbackContext *context,
lldb::user_id_t watch_id);
// PluginInterface protocol
lldb_private::ConstString GetPluginName() override;
@ -77,9 +82,16 @@ public:
std::vector<std::reference_wrapper<BreakpointOptions>> &bp_options_vec,
CommandReturnObject &result) override;
void
CollectDataForWatchpointCommandCallback(WatchpointOptions *wp_options,
CommandReturnObject &result) override;
Status SetBreakpointCommandCallback(BreakpointOptions &bp_options,
const char *command_body_text) override;
void SetWatchpointCommandCallback(WatchpointOptions *wp_options,
const char *command_body_text) override;
Status SetBreakpointCommandCallbackFunction(
BreakpointOptions &bp_options, const char *function_name,
StructuredData::ObjectSP extra_args_sp) override;
@ -91,6 +103,10 @@ private:
Status RegisterBreakpointCallback(BreakpointOptions &bp_options,
const char *command_body_text,
StructuredData::ObjectSP extra_args_sp);
Status RegisterWatchpointCallback(WatchpointOptions *wp_options,
const char *command_body_text,
StructuredData::ObjectSP extra_args_sp);
};
} // namespace lldb_private

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@ -1,9 +1,33 @@
# REQUIRES: lua
# XFAIL: system-netbsd
# RUN: echo "int main() { return 0; }" | %clang_host -x c - -o %t
# RUN: echo "int main() { int val = 1; val++; return 0; }" | %clang_host -x c - -g -o %t
# RUN: %lldb -s %s --script-language lua %t 2>&1 | FileCheck %s
b main
r
watchpoint set expr 0x0
watchpoint set variable val
watchpoint command add -s lua
# CHECK: error: This script interpreter does not support watchpoint callbacks
print("val=" .. tostring(frame:FindVariable("val"):GetValue()))
quit
c
# CHECK: val=1
# CHECK: val=2
# CHECK: Process {{[0-9]+}} exited
r
watchpoint set variable val
watchpoint modify 1 -c "(val == 1)"
watchpoint command add -s lua
print("conditional watchpoint")
wp:SetEnabled(false)
quit
c
# CHECK-COUNT-1: conditional watchpoint
# CHECK-NOT: conditional watchpoint
# CHECK: Process {{[0-9]+}} exited
r
watchpoint set expr 0x00
watchpoint command add -s lua
print("never triggers")
quit
c
# CHECK-NOT: never triggers
# CHECK: Process {{[0-9]+}} exited

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@ -30,6 +30,11 @@ extern "C" llvm::Expected<bool> LLDBSwigLuaBreakpointCallbackFunction(
return false;
}
extern "C" llvm::Expected<bool> LLDBSwigLuaWatchpointCallbackFunction(
lua_State *L, lldb::StackFrameSP stop_frame_sp, lldb::WatchpointSP wp_sp) {
return false;
}
#if _MSC_VER
#pragma warning (pop)
#endif