[Lldb-commits] [lldb] a0d7406 - [LLDB/Lua] add support for one-liner breakpoint callback
Pedro Tammela via lldb-commits
lldb-commits at lists.llvm.org
Mon Nov 30 06:12:35 PST 2020
Author: Pedro Tammela
Date: 2020-11-30T14:12:26Z
New Revision: a0d7406ae800c45dd9cb438c7ae1f55329d198e2
URL: https://github.com/llvm/llvm-project/commit/a0d7406ae800c45dd9cb438c7ae1f55329d198e2
DIFF: https://github.com/llvm/llvm-project/commit/a0d7406ae800c45dd9cb438c7ae1f55329d198e2.diff
LOG: [LLDB/Lua] add support for one-liner breakpoint callback
These callbacks are set using the following:
breakpoint command add -s lua -o "print('hello world!')"
The user supplied script is executed as:
function (frame, bp_loc, ...)
<body>
end
So the local variables 'frame', 'bp_loc' and vararg are all accessible.
Any global variables declared will persist in the Lua interpreter.
A user should never hold 'frame' and 'bp_loc' in a global variable as
these userdatas are context dependent.
Differential Revision: https://reviews.llvm.org/D91508
Added:
lldb/bindings/lua/lua-swigsafecast.swig
lldb/bindings/lua/lua-wrapper.swig
lldb/test/Shell/ScriptInterpreter/Lua/breakpoint_oneline_callback.test
Modified:
lldb/bindings/lua/lua.swig
lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h
lldb/unittests/ScriptInterpreter/Lua/LuaTests.cpp
Removed:
################################################################################
diff --git a/lldb/bindings/lua/lua-swigsafecast.swig b/lldb/bindings/lua/lua-swigsafecast.swig
new file mode 100644
index 000000000000..d19308976899
--- /dev/null
+++ b/lldb/bindings/lua/lua-swigsafecast.swig
@@ -0,0 +1,15 @@
+template <typename SBClass>
+void
+PushSBClass (lua_State* L, SBClass* obj);
+
+void
+PushSBClass (lua_State* L, lldb::SBFrame* frame_sb)
+{
+ SWIG_NewPointerObj(L, frame_sb, SWIGTYPE_p_lldb__SBFrame, 0);
+}
+
+void
+PushSBClass (lua_State* L, lldb::SBBreakpointLocation* breakpoint_location_sb)
+{
+ SWIG_NewPointerObj(L, breakpoint_location_sb, SWIGTYPE_p_lldb__SBBreakpointLocation, 0);
+}
diff --git a/lldb/bindings/lua/lua-wrapper.swig b/lldb/bindings/lua/lua-wrapper.swig
new file mode 100644
index 000000000000..4e3df74999dc
--- /dev/null
+++ b/lldb/bindings/lua/lua-wrapper.swig
@@ -0,0 +1,46 @@
+%header %{
+
+template <typename T>
+void
+PushSBClass(lua_State* L, T* obj);
+
+%}
+
+%wrapper %{
+
+// This function is called from Lua::CallBreakpointCallback
+SWIGEXPORT llvm::Expected<bool>
+LLDBSwigLuaBreakpointCallbackFunction
+(
+ lua_State *L,
+ lldb::StackFrameSP stop_frame_sp,
+ lldb::BreakpointLocationSP bp_loc_sp
+)
+{
+ lldb::SBFrame sb_frame(stop_frame_sp);
+ lldb::SBBreakpointLocation sb_bp_loc(bp_loc_sp);
+
+ // Push the Lua wrappers
+ PushSBClass(L, &sb_frame);
+ PushSBClass(L, &sb_bp_loc);
+
+ // Call into the Lua callback passing 'sb_frame' and 'sb_bp_loc'.
+ // Expects a boolean return.
+ if (lua_pcall(L, 2, 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;
+}
+
+
+%}
diff --git a/lldb/bindings/lua/lua.swig b/lldb/bindings/lua/lua.swig
index 524d1b5a8036..c702e4964081 100644
--- a/lldb/bindings/lua/lua.swig
+++ b/lldb/bindings/lua/lua.swig
@@ -14,8 +14,12 @@
%include "headers.swig"
%{
+#include "llvm/Support/Error.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "../bindings/lua/lua-swigsafecast.swig"
using namespace lldb_private;
using namespace lldb;
%}
%include "interfaces.swig"
+%include "lua-wrapper.swig"
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
index dc3fd84a3bfb..ca1d181a6940 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
@@ -9,11 +9,34 @@
#include "Lua.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Utility/FileSpec.h"
+#include "llvm/Support/Error.h"
#include "llvm/Support/FormatVariadic.h"
using namespace lldb_private;
using namespace lldb;
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
+
+// Disable warning C4190: 'LLDBSwigPythonBreakpointCallbackFunction' has
+// C-linkage specified, but returns UDT 'llvm::Expected<bool>' which is
+// incompatible with C
+#if _MSC_VER
+#pragma warning (push)
+#pragma warning (disable : 4190)
+#endif
+
+extern "C" llvm::Expected<bool>
+LLDBSwigLuaBreakpointCallbackFunction(lua_State *L,
+ lldb::StackFrameSP stop_frame_sp,
+ lldb::BreakpointLocationSP bp_loc_sp);
+
+#if _MSC_VER
+#pragma warning (pop)
+#endif
+
+#pragma clang diagnostic pop
+
static int lldb_print(lua_State *L) {
int n = lua_gettop(L);
lua_getglobal(L, "io");
@@ -57,6 +80,31 @@ llvm::Error Lua::Run(llvm::StringRef buffer) {
return e;
}
+llvm::Error Lua::RegisterBreakpointCallback(void *baton, const char *body) {
+ lua_pushlightuserdata(m_lua_state, baton);
+ const char *fmt_str = "return function(frame, bp_loc, ...) {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}\n", 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::CallBreakpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
+ lldb::BreakpointLocationSP bp_loc_sp) {
+ lua_pushlightuserdata(m_lua_state, baton);
+ lua_gettable(m_lua_state, LUA_REGISTRYINDEX);
+ return LLDBSwigLuaBreakpointCallbackFunction(m_lua_state, stop_frame_sp,
+ bp_loc_sp);
+}
+
llvm::Error Lua::LoadModule(llvm::StringRef filename) {
FileSpec file(filename);
if (!FileSystem::Instance().Exists(file)) {
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
index 83f836d8d78a..39c39e1c43b8 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
@@ -9,6 +9,8 @@
#ifndef liblldb_Lua_h_
#define liblldb_Lua_h_
+#include "lldb/API/SBBreakpointLocation.h"
+#include "lldb/API/SBFrame.h"
#include "lldb/lldb-types.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
@@ -29,6 +31,10 @@ class Lua {
~Lua();
llvm::Error Run(llvm::StringRef buffer);
+ llvm::Error RegisterBreakpointCallback(void *baton, const char *body);
+ llvm::Expected<bool>
+ CallBreakpointCallback(void *baton, lldb::StackFrameSP stop_frame_sp,
+ lldb::BreakpointLocationSP bp_loc_sp);
llvm::Error LoadModule(llvm::StringRef filename);
llvm::Error ChangeIO(FILE *out, FILE *err);
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
index 6fe196a36abe..6672363164b1 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
@@ -8,14 +8,17 @@
#include "ScriptInterpreterLua.h"
#include "Lua.h"
+#include "lldb/Breakpoint/StoppointCallbackContext.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Interpreter/CommandReturnObject.h"
+#include "lldb/Target/ExecutionContext.h"
#include "lldb/Utility/Stream.h"
#include "lldb/Utility/StringList.h"
#include "lldb/Utility/Timer.h"
#include "llvm/Support/FormatAdapters.h"
+#include <memory>
using namespace lldb;
using namespace lldb_private;
@@ -174,6 +177,49 @@ llvm::Error ScriptInterpreterLua::LeaveSession() {
return m_lua->Run(str);
}
+bool ScriptInterpreterLua::BreakpointCallbackFunction(
+ void *baton, StoppointCallbackContext *context, user_id_t break_id,
+ user_id_t break_loc_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());
+ BreakpointSP breakpoint_sp = target->GetBreakpointByID(break_id);
+ BreakpointLocationSP bp_loc_sp(breakpoint_sp->FindLocationByID(break_loc_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.CallBreakpointCallback(baton, stop_frame_sp, bp_loc_sp);
+ if (llvm::Error E = BoolOrErr.takeError()) {
+ debugger.GetErrorStream() << toString(std::move(E));
+ return true;
+ }
+
+ return *BoolOrErr;
+}
+
+Status ScriptInterpreterLua::SetBreakpointCommandCallback(
+ BreakpointOptions *bp_options, const char *command_body_text) {
+ Status error;
+ auto data_up = std::make_unique<CommandDataLua>();
+ error = m_lua->RegisterBreakpointCallback(data_up.get(), command_body_text);
+ if (error.Fail())
+ return error;
+ auto baton_sp =
+ std::make_shared<BreakpointOptions::CommandBaton>(std::move(data_up));
+ bp_options->SetCallback(ScriptInterpreterLua::BreakpointCallbackFunction,
+ baton_sp);
+ return error;
+}
+
lldb::ScriptInterpreterSP
ScriptInterpreterLua::CreateInstance(Debugger &debugger) {
return std::make_shared<ScriptInterpreterLua>(debugger);
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h
index 004222b94798..1238b8922bc1 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h
@@ -10,11 +10,20 @@
#define liblldb_ScriptInterpreterLua_h_
#include "lldb/Interpreter/ScriptInterpreter.h"
+#include "lldb/Utility/Status.h"
+#include "lldb/lldb-enumerations.h"
namespace lldb_private {
class Lua;
class ScriptInterpreterLua : public ScriptInterpreter {
public:
+ class CommandDataLua : public BreakpointOptions::CommandData {
+ public:
+ CommandDataLua() : BreakpointOptions::CommandData() {
+ interpreter = lldb::eScriptLanguageLua;
+ }
+ };
+
ScriptInterpreterLua(Debugger &debugger);
~ScriptInterpreterLua() override;
@@ -41,6 +50,11 @@ class ScriptInterpreterLua : public ScriptInterpreter {
static const char *GetPluginDescriptionStatic();
+ static bool BreakpointCallbackFunction(void *baton,
+ StoppointCallbackContext *context,
+ lldb::user_id_t break_id,
+ lldb::user_id_t break_loc_id);
+
// PluginInterface protocol
lldb_private::ConstString GetPluginName() override;
@@ -51,6 +65,9 @@ class ScriptInterpreterLua : public ScriptInterpreter {
llvm::Error EnterSession(lldb::user_id_t debugger_id);
llvm::Error LeaveSession();
+ Status SetBreakpointCommandCallback(BreakpointOptions *bp_options,
+ const char *command_body_text) override;
+
private:
std::unique_ptr<Lua> m_lua;
bool m_session_is_active = false;
diff --git a/lldb/test/Shell/ScriptInterpreter/Lua/breakpoint_oneline_callback.test b/lldb/test/Shell/ScriptInterpreter/Lua/breakpoint_oneline_callback.test
new file mode 100644
index 000000000000..ef07a8af4d1f
--- /dev/null
+++ b/lldb/test/Shell/ScriptInterpreter/Lua/breakpoint_oneline_callback.test
@@ -0,0 +1,18 @@
+# REQUIRES: lua
+# RUN: echo "int main() { return 0; }" | %clang_host -x c - -o %t
+# RUN: %lldb -s %s --script-language lua %t 2>&1 | FileCheck %s
+b main
+breakpoint command add -s lua -o 'return false'
+run
+# CHECK: Process {{[0-9]+}} exited with status = 0
+breakpoint command add -s lua -o 'print(bacon)'
+run
+# CHECK: bacon
+# CHECK: Process {{[0-9]+}} exited with status = 0
+breakpoint command add -s lua -o "return true"
+run
+# CHECK: Process {{[0-9]+}} stopped
+breakpoint command add -s lua -o 'error("my error message")'
+run
+# CHECK: my error message
+# CHECK: Process {{[0-9]+}} stopped
diff --git a/lldb/unittests/ScriptInterpreter/Lua/LuaTests.cpp b/lldb/unittests/ScriptInterpreter/Lua/LuaTests.cpp
index 464babcb290a..74578af8e76e 100644
--- a/lldb/unittests/ScriptInterpreter/Lua/LuaTests.cpp
+++ b/lldb/unittests/ScriptInterpreter/Lua/LuaTests.cpp
@@ -13,6 +13,30 @@ using namespace lldb_private;
extern "C" int luaopen_lldb(lua_State *L) { return 0; }
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
+
+// Disable warning C4190: 'LLDBSwigPythonBreakpointCallbackFunction' has
+// C-linkage specified, but returns UDT 'llvm::Expected<bool>' which is
+// incompatible with C
+#if _MSC_VER
+#pragma warning (push)
+#pragma warning (disable : 4190)
+#endif
+
+extern "C" llvm::Expected<bool>
+LLDBSwigLuaBreakpointCallbackFunction(lua_State *L,
+ lldb::StackFrameSP stop_frame_sp,
+ lldb::BreakpointLocationSP bp_loc_sp) {
+ return false;
+}
+
+#if _MSC_VER
+#pragma warning (pop)
+#endif
+
+#pragma clang diagnostic pop
+
TEST(LuaTest, RunValid) {
Lua lua;
llvm::Error error = lua.Run("foo = 1");
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