Index: lldb/include/lldb/Breakpoint/Watchpoint.h =================================================================== --- lldb/include/lldb/Breakpoint/Watchpoint.h +++ lldb/include/lldb/Breakpoint/Watchpoint.h @@ -90,6 +90,40 @@ void SetWatchVariable(bool val); bool CaptureWatchedValue(const ExecutionContext &exe_ctx); + /// \struct WatchpointVariableContext + /// \brief Represents the context of a watchpoint variable. + /// + /// This struct encapsulates the information related to a watchpoint variable, + /// including the watch ID and the execution context in which it is being + /// used. This struct is passed as a Baton to the \b + /// VariableWatchpointDisabler breakpoint callback. + struct WatchpointVariableContext { + /// \brief Constructor for WatchpointVariableContext. + /// \param watch_id The ID of the watchpoint. + /// \param exe_ctx The execution context associated with the watchpoint. + WatchpointVariableContext(lldb::watch_id_t watch_id, + ExecutionContext exe_ctx) + : watch_id(watch_id), exe_ctx(exe_ctx) {} + + lldb::watch_id_t watch_id; ///< The ID of the watchpoint. + ExecutionContext + exe_ctx; ///< The execution context associated with the watchpoint. + }; + + class WatchpointVariableBaton : public TypedBaton { + public: + WatchpointVariableBaton(std::unique_ptr Data) + : TypedBaton(std::move(Data)) {} + }; + + bool SetupVariableWatchpointDisabler(lldb::StackFrameSP frame_sp) const; + + /// Callback routine to disable the watchpoint set on a local variable when + /// it goes out of scope. + static bool VariableWatchpointDisabler( + void *baton, lldb_private::StoppointCallbackContext *context, + lldb::user_id_t break_id, lldb::user_id_t break_loc_id); + void GetDescription(Stream *s, lldb::DescriptionLevel level); void Dump(Stream *s) const override; void DumpSnapshots(Stream *s, const char *prefix = nullptr) const; Index: lldb/source/Breakpoint/Watchpoint.cpp =================================================================== --- lldb/source/Breakpoint/Watchpoint.cpp +++ lldb/source/Breakpoint/Watchpoint.cpp @@ -83,6 +83,94 @@ SendWatchpointChangedEvent(eWatchpointEventTypeCommandChanged); } +bool Watchpoint::SetupVariableWatchpointDisabler(StackFrameSP frame_sp) const { + if (!frame_sp) + return false; + + ThreadSP thread_sp = frame_sp->GetThread(); + if (!thread_sp) + return false; + + uint32_t return_frame_index = + thread_sp->GetSelectedFrameIndex(DoNoSelectMostRelevantFrame) + 1; + if (return_frame_index >= LLDB_INVALID_FRAME_ID) + return false; + + StackFrameSP return_frame_sp( + thread_sp->GetStackFrameAtIndex(return_frame_index)); + if (!return_frame_sp) + return false; + + ExecutionContext exe_ctx(return_frame_sp); + TargetSP target_sp = exe_ctx.GetTargetSP(); + if (!target_sp) + return false; + + Address return_address(return_frame_sp->GetFrameCodeAddress()); + lldb::addr_t return_addr = return_address.GetLoadAddress(target_sp.get()); + if (return_addr == LLDB_INVALID_ADDRESS) + return false; + + BreakpointSP bp_sp = target_sp->CreateBreakpoint( + return_addr, /*internal=*/true, /*request_hardware=*/false); + if (!bp_sp || !bp_sp->HasResolvedLocations()) + return false; + + auto wvc_up = std::make_unique(GetID(), exe_ctx); + auto baton_sp = std::make_shared(std::move(wvc_up)); + bp_sp->SetCallback(VariableWatchpointDisabler, baton_sp); + bp_sp->SetOneShot(true); + bp_sp->SetBreakpointKind("variable watchpoint disabler"); + return true; +} + +bool Watchpoint::VariableWatchpointDisabler(void *baton, + StoppointCallbackContext *context, + user_id_t break_id, + user_id_t break_loc_id) { + assert(baton && "null baton"); + if (!baton || !context) + return false; + + Log *log = GetLog(LLDBLog::Watchpoints); + + WatchpointVariableContext *wvc = + static_cast(baton); + + LLDB_LOGF(log, "Watchpoint::%s called by breakpoint %" PRIu64 ".%" PRIu64, + __FUNCTION__, break_id, break_loc_id); + + if (wvc->watch_id == LLDB_INVALID_WATCH_ID) + return false; + + TargetSP target_sp = context->exe_ctx_ref.GetTargetSP(); + if (!target_sp) + return false; + + ProcessSP process_sp = target_sp->GetProcessSP(); + if (!process_sp) + return false; + + WatchpointSP watch_sp = + target_sp->GetWatchpointList().FindByID(wvc->watch_id); + if (!watch_sp) + return false; + + if (wvc->exe_ctx == context->exe_ctx_ref) { + LLDB_LOGF(log, + "Watchpoint::%s callback for watchpoint %" PRId32 + " matched internal breakpoint execution context", + __FUNCTION__, watch_sp->GetID()); + process_sp->DisableWatchpoint(watch_sp.get()); + return false; + } + LLDB_LOGF(log, + "Watchpoint::%s callback for watchpoint %" PRId32 + " didn't match internal breakpoint execution context", + __FUNCTION__, watch_sp->GetID()); + return false; +} + void Watchpoint::ClearCallback() { m_options.ClearCallback(); SendWatchpointChangedEvent(eWatchpointEventTypeCommandChanged); Index: lldb/source/Commands/CommandObjectWatchpoint.cpp =================================================================== --- lldb/source/Commands/CommandObjectWatchpoint.cpp +++ lldb/source/Commands/CommandObjectWatchpoint.cpp @@ -9,6 +9,7 @@ #include "CommandObjectWatchpoint.h" #include "CommandObjectWatchpointCommand.h" +#include #include #include "llvm/ADT/StringRef.h" @@ -20,6 +21,7 @@ #include "lldb/Interpreter/CommandInterpreter.h" #include "lldb/Interpreter/CommandOptionArgumentTable.h" #include "lldb/Interpreter/CommandReturnObject.h" +#include "lldb/Symbol/Function.h" #include "lldb/Symbol/Variable.h" #include "lldb/Symbol/VariableList.h" #include "lldb/Target/StackFrame.h" @@ -950,27 +952,32 @@ error.Clear(); WatchpointSP watch_sp = target->CreateWatchpoint(addr, size, &compiler_type, watch_type, error); - if (watch_sp) { - watch_sp->SetWatchSpec(command.GetArgumentAtIndex(0)); - watch_sp->SetWatchVariable(true); - if (var_sp && var_sp->GetDeclaration().GetFile()) { - StreamString ss; - // True to show fullpath for declaration file. - var_sp->GetDeclaration().DumpStopContext(&ss, true); - watch_sp->SetDeclInfo(std::string(ss.GetString())); - } - output_stream.Printf("Watchpoint created: "); - watch_sp->GetDescription(&output_stream, lldb::eDescriptionLevelFull); - output_stream.EOL(); - result.SetStatus(eReturnStatusSuccessFinishResult); - } else { + if (!watch_sp) { result.AppendErrorWithFormat( "Watchpoint creation failed (addr=0x%" PRIx64 ", size=%" PRIu64 ", variable expression='%s').\n", addr, (uint64_t)size, command.GetArgumentAtIndex(0)); if (error.AsCString(nullptr)) result.AppendError(error.AsCString()); + return result.Succeeded(); + } + + watch_sp->SetWatchSpec(command.GetArgumentAtIndex(0)); + watch_sp->SetWatchVariable(true); + if (var_sp) { + if (var_sp->GetDeclaration().GetFile()) { + StreamString ss; + // True to show fullpath for declaration file. + var_sp->GetDeclaration().DumpStopContext(&ss, true); + watch_sp->SetDeclInfo(std::string(ss.GetString())); + } + if (var_sp->GetScope() == eValueTypeVariableLocal) + watch_sp->SetupVariableWatchpointDisabler(m_exe_ctx.GetFrameSP()); } + output_stream.Printf("Watchpoint created: "); + watch_sp->GetDescription(&output_stream, lldb::eDescriptionLevelFull); + output_stream.EOL(); + result.SetStatus(eReturnStatusSuccessFinishResult); return result.Succeeded(); } Index: lldb/test/Shell/ScriptInterpreter/Lua/watchpoint_callback.test =================================================================== --- lldb/test/Shell/ScriptInterpreter/Lua/watchpoint_callback.test +++ lldb/test/Shell/ScriptInterpreter/Lua/watchpoint_callback.test @@ -1,4 +1,4 @@ -# XFAIL: system-netbsd, system-darwin +# XFAIL: system-netbsd # RUN: %clang_host -x c %S/Inputs/val.c -g -o %t # RUN: %lldb -b -s %S/Inputs/watchpoint1.in --script-language lua %t 2>&1 | FileCheck %S/Inputs/watchpoint1.in # RUN: %lldb -b -s %S/Inputs/watchpoint2.in --script-language lua %t 2>&1 | FileCheck %S/Inputs/watchpoint2.in Index: lldb/test/Shell/Watchpoint/Inputs/val.c =================================================================== --- /dev/null +++ lldb/test/Shell/Watchpoint/Inputs/val.c @@ -0,0 +1,7 @@ +int main() { + int val = 0; + // Break here + val++; + val++; + return 0; +} Index: lldb/test/Shell/Watchpoint/Inputs/watchpoint.in =================================================================== --- /dev/null +++ lldb/test/Shell/Watchpoint/Inputs/watchpoint.in @@ -0,0 +1,13 @@ +breakpoint set -p "Break here" +r +watchpoint set variable val +watchpoint modify -c "val == 1" +c +# CHECK: Watchpoint 1 hit: +# CHECK-NEXT: old value: 0 +# CHECK-NEXT: new value: 1 +# CHECK-NEXT: Process {{[0-9]+}} resuming +# CHECK-NEXT: Process {{[0-9]+}} stopped +# CHECK-NEXT: {{.*}} stop reason = watchpoint 1 +c +# CHECK: Process {{[0-9]+}} exited with status = 0 (0x00000000) Index: lldb/test/Shell/Watchpoint/LocalVariableWatchpointDisabler.test =================================================================== --- /dev/null +++ lldb/test/Shell/Watchpoint/LocalVariableWatchpointDisabler.test @@ -0,0 +1,3 @@ +# XFAIL: system-netbsd +# RUN: %clang_host -x c %S/Inputs/val.c -g -o %t +# RUN: %lldb -b -s %S/Inputs/watchpoint.in %t 2>&1 | FileCheck %S/Inputs/watchpoint.in