[Lldb-commits] [lldb] b68f6c0 - [lldb] Override UpdateBreakpointSites in ProcessGDBRemote to use MultiBreakpoint (#192988)
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Wed May 6 23:59:42 PDT 2026
Author: Felipe de Azevedo Piovezan
Date: 2026-05-07T07:59:37+01:00
New Revision: b68f6c0e8b0041d3be213ae2623f00b9189648de
URL: https://github.com/llvm/llvm-project/commit/b68f6c0e8b0041d3be213ae2623f00b9189648de
DIFF: https://github.com/llvm/llvm-project/commit/b68f6c0e8b0041d3be213ae2623f00b9189648de.diff
LOG: [lldb] Override UpdateBreakpointSites in ProcessGDBRemote to use MultiBreakpoint (#192988)
This concludes the implementation of MultiBreakpoint by actually using
the new packet to batch breakpoint requests.
The following PRs are related to the MultiBreakpoint feature:
* https://github.com/llvm/llvm-project/pull/192910
* https://github.com/llvm/llvm-project/pull/192914
* https://github.com/llvm/llvm-project/pull/192915
* https://github.com/llvm/llvm-project/pull/192919
* https://github.com/llvm/llvm-project/pull/192962
* https://github.com/llvm/llvm-project/pull/192964
* https://github.com/llvm/llvm-project/pull/192971
* https://github.com/llvm/llvm-project/pull/192988
Added:
Modified:
lldb/include/lldb/Utility/GDBRemote.h
lldb/packages/Python/lldbsuite/test/lldbreverse.py
lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
lldb/source/Target/Target.cpp
lldb/source/Utility/GDBRemote.cpp
lldb/test/API/functionalities/breakpoint/delayed_breakpoints/TestDelayedBreakpoint.py
Removed:
################################################################################
diff --git a/lldb/include/lldb/Utility/GDBRemote.h b/lldb/include/lldb/Utility/GDBRemote.h
index 3b839c5d79485..ab33f02ebb012 100644
--- a/lldb/include/lldb/Utility/GDBRemote.h
+++ b/lldb/include/lldb/Utility/GDBRemote.h
@@ -42,6 +42,9 @@ class StreamGDBRemote : public StreamString {
/// Number of bytes written.
// TODO: Convert this function to take ArrayRef<uint8_t>
int PutEscapedBytes(const void *s, size_t src_len);
+
+ /// Equivalent to PutEscapedBytes(str.data(), str.size());
+ int PutEscapedBytes(llvm::StringRef str);
};
/// GDB remote packet as used by the GDB remote communication history. Packets
diff --git a/lldb/packages/Python/lldbsuite/test/lldbreverse.py b/lldb/packages/Python/lldbsuite/test/lldbreverse.py
index d9a8daba3772d..50b97b5597f3a 100644
--- a/lldb/packages/Python/lldbsuite/test/lldbreverse.py
+++ b/lldb/packages/Python/lldbsuite/test/lldbreverse.py
@@ -5,6 +5,7 @@
from lldbsuite.test.gdbclientutils import *
from lldbsuite.test.lldbgdbproxy import *
import lldbgdbserverutils
+import json
import re
@@ -132,6 +133,10 @@ def respond(self, packet):
if reply == "OK":
self.update_breakpoints(packet)
return reply
+ if packet.startswith("jMultiBreakpoint:"):
+ reply = self.pass_through(packet)
+ self.update_multi_breakpoints(packet, reply)
+ return reply
return GDBProxyTestBase.respond(self, packet)
def start_recording(self):
@@ -161,6 +166,23 @@ def update_breakpoints(self, packet):
else:
self.breakpoints[t].discard((addr, kind))
+ def update_multi_breakpoints(self, packet, reply):
+ # Remove the final ], which is binary-escaping the }.
+ packet = packet[:-1]
+ reply = reply[:-1]
+ body = packet[len("jMultiBreakpoint:") :]
+ requests = json.loads(body)["breakpoint_requests"]
+ try:
+ results = json.loads(reply)["results"]
+ except (ValueError, KeyError):
+ # Empty/unsupported/error reply: nothing was installed.
+ return
+ if len(requests) != len(results):
+ raise ValueError("jMultiBreakpoint response count mismatch")
+ for inner_packet, result in zip(requests, results):
+ if result == "OK":
+ self.update_breakpoints(inner_packet)
+
def breakpoint_triggered_at(self, pc):
if any(addr == pc for addr, kind in self.breakpoints[SOFTWARE_BREAKPOINTS]):
return True
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
index 406fa06ea011a..fa927b74d56fa 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
@@ -9,6 +9,7 @@
#include "GDBRemoteClientBase.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/ErrorExtras.h"
#include "lldb/Target/UnixSignals.h"
#include "lldb/Utility/LLDBAssert.h"
@@ -194,6 +195,22 @@ GDBRemoteClientBase::SendPacketAndWaitForResponse(
return SendPacketAndWaitForResponseNoLock(payload, response, sync_on_timeout);
}
+llvm::Expected<StringExtractorGDBRemote>
+GDBRemoteClientBase::SendPacketAndExpectResponse(
+ llvm::StringRef payload, std::chrono::seconds interrupt_timeout) {
+ StringExtractorGDBRemote response;
+ GDBRemoteCommunication::PacketResult packet_result =
+ SendPacketAndWaitForResponse(payload, response, interrupt_timeout);
+ if (packet_result != GDBRemoteCommunication::PacketResult::Success)
+ return llvm::createStringErrorV("failed to send packet: '{0}'", payload);
+
+ if (response.IsUnsupportedResponse())
+ return llvm::createStringErrorV("unsupported response: '{0}'",
+ response.GetStringRef());
+
+ return std::move(response);
+}
+
GDBRemoteCommunication::PacketResult
GDBRemoteClientBase::ReadPacketWithOutputSupport(
StringExtractorGDBRemote &response, Timeout<std::micro> timeout,
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
index 9c17a8c1de057..65738491c21dd 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
@@ -74,6 +74,11 @@ class GDBRemoteClientBase : public GDBRemoteCommunication, public Broadcaster {
std::chrono::seconds interrupt_timeout,
llvm::function_ref<void(llvm::StringRef)> output_callback);
+ /// Wrapper around SendPacketAndWaitForResponse that returns an `Expected`.
+ llvm::Expected<StringExtractorGDBRemote> SendPacketAndExpectResponse(
+ llvm::StringRef payload,
+ std::chrono::seconds interrupt_timeout = std::chrono::seconds(0));
+
class Lock {
public:
// If interrupt_timeout == 0 seconds, only take the lock if the target is
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 10778bdf57ac9..8f55277f4a788 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -6391,3 +6391,173 @@ void ProcessGDBRemote::DidExec() {
}
Process::DidExec();
}
+
+llvm::Error ProcessGDBRemote::UpdateBreakpointSitesNotBatched(
+ const BreakpointSiteToActionMap &site_to_action) {
+ llvm::Error joined = llvm::Error::success();
+ for (auto &[site, action] : site_to_action) {
+ llvm::Error error = action == Process::BreakpointAction::Enable
+ ? DoEnableBreakpointSite(*site)
+ : DoDisableBreakpointSite(*site);
+ joined = llvm::joinErrors(std::move(joined), std::move(error));
+ }
+ return joined;
+}
+
+/// Parse a MultiBreakpoint response into per-request results.
+/// Returns a vector of results: std::nullopt means OK, a uint8_t value is the
+/// error code from an Exx response.
+static llvm::SmallVector<std::optional<uint8_t>>
+ParseMultiBreakpointResponse(llvm::StringRef response_str) {
+ llvm::SmallVector<std::optional<uint8_t>> results;
+
+ StructuredData::ObjectSP parsed = StructuredData::ParseJSON(response_str);
+ StructuredData::Dictionary *dict =
+ parsed ? parsed->GetAsDictionary() : nullptr;
+ StructuredData::Array *array = nullptr;
+ if (dict)
+ dict->GetValueForKeyAsArray("results", array);
+ if (!array)
+ return results;
+
+ array->ForEach([&results](StructuredData::Object *object) -> bool {
+ llvm::StringRef token;
+ if (auto *string = object->GetAsString())
+ token = string->GetValue();
+ if (token == "OK") {
+ results.push_back(std::nullopt);
+ return true;
+ }
+ if (token.size() != 3 || !token.starts_with("E")) {
+ results.push_back(uint8_t(0xff));
+ return true;
+ }
+ uint8_t error_code = 0;
+ if (token.drop_front(1).getAsInteger(16, error_code))
+ results.push_back(0xff);
+ else
+ results.push_back(error_code);
+ return true;
+ });
+ return results;
+}
+
+/// Determine the GDB stoppoint type for a breakpoint site by checking which
+/// packet types the remote supports (for insertions), or by checking the site
+/// type (for deletions).
+static std::optional<GDBStoppointType>
+GetStoppointType(BreakpointSite &site, bool insert,
+ GDBRemoteCommunicationClient &gdb_comm) {
+ if (insert) {
+ if (!site.HardwareRequired() &&
+ gdb_comm.SupportsGDBStoppointPacket(eBreakpointSoftware))
+ return eBreakpointSoftware;
+ if (gdb_comm.SupportsGDBStoppointPacket(eBreakpointHardware))
+ return eBreakpointHardware;
+ return std::nullopt;
+ }
+
+ switch (site.GetType()) {
+ case BreakpointSite::eExternal:
+ return eBreakpointSoftware;
+ case BreakpointSite::eHardware:
+ return eBreakpointHardware;
+ case BreakpointSite::eSoftware:
+ return std::nullopt;
+ }
+ llvm_unreachable("unhandled BreakpointSite type");
+}
+
+namespace {
+struct BreakpointPacketInfo {
+ BreakpointSite &site;
+ size_t trap_opcode_size;
+ GDBStoppointType type;
+ bool is_enable;
+};
+
+std::string to_string(const BreakpointPacketInfo &info) {
+ char packet = info.is_enable ? 'Z' : 'z';
+ return llvm::formatv("{0}{1},{2:x-},{3:x-}", packet,
+ static_cast<int>(info.type), info.site.GetLoadAddress(),
+ info.trap_opcode_size)
+ .str();
+}
+} // namespace
+
+llvm::Error ProcessGDBRemote::UpdateBreakpointSites(
+ const BreakpointSiteToActionMap &site_to_action) {
+ if (site_to_action.empty())
+ return llvm::Error::success();
+ if (!m_gdb_comm.GetMultiBreakpointSupported())
+ return UpdateBreakpointSitesNotBatched(site_to_action);
+
+ Log *log = GetLog(GDBRLog::Breakpoints);
+
+ std::vector<BreakpointPacketInfo> breakpoint_infos;
+ for (auto [site, action] : site_to_action) {
+ size_t trap_opcode_size = GetSoftwareBreakpointTrapOpcode(site.get());
+ std::optional<GDBStoppointType> type =
+ GetStoppointType(*site, action == BreakpointAction::Enable, m_gdb_comm);
+
+ if (!type) {
+ LLDB_LOG(log, "MultiBreakpoint: site {0} at {1:x} can't be batched",
+ site->GetID(), site->GetLoadAddress());
+ return UpdateBreakpointSitesNotBatched(site_to_action);
+ }
+
+ breakpoint_infos.push_back(
+ {*site, trap_opcode_size, *type, action == BreakpointAction::Enable});
+ }
+
+ StreamString stream;
+ stream << "jMultiBreakpoint:";
+
+ auto args_array = std::make_shared<StructuredData::Array>();
+ for (auto &bp_info : breakpoint_infos)
+ args_array->AddStringItem(to_string(bp_info));
+
+ StructuredData::Dictionary packet_dict;
+ packet_dict.AddItem("breakpoint_requests", args_array);
+ packet_dict.Dump(stream, false);
+
+ StreamGDBRemote escaped_stream;
+ escaped_stream.PutEscapedBytes(stream.GetString());
+ llvm::Expected<StringExtractorGDBRemote> response =
+ m_gdb_comm.SendPacketAndExpectResponse(escaped_stream.GetString(),
+ GetInterruptTimeout());
+
+ if (!response) {
+ LLDB_LOG_ERROR(log, response.takeError(), "jMultiBreakpoint failed: {0}");
+ return UpdateBreakpointSitesNotBatched(site_to_action);
+ }
+
+ llvm::SmallVector<std::optional<uint8_t>> results =
+ ParseMultiBreakpointResponse(response->GetStringRef());
+
+ // This is a protocol violation, do nothing.
+ if (results.size() != breakpoint_infos.size())
+ return llvm::createStringErrorV(
+ "MultiBreakpoint response count mismatch (expected {0}, got {1})",
+ site_to_action.size(), results.size());
+
+ llvm::Error joined = llvm::Error::success();
+ for (auto [error_code, bp_info] :
+ llvm::zip_equal(results, breakpoint_infos)) {
+ BreakpointSite &site = bp_info.site;
+ if (error_code) {
+ auto error = llvm::createStringErrorV(
+ "MultiBreakpoint: site {0} at {1:x} failed with E{2}",
+ bp_info.site.GetID(), bp_info.site.GetLoadAddress(), error_code);
+ joined = llvm::joinErrors(std::move(joined), std::move(error));
+ continue;
+ }
+ SetBreakpointSiteEnabled(site, bp_info.is_enable);
+ if (bp_info.is_enable)
+ site.SetType(bp_info.type == eBreakpointHardware
+ ? BreakpointSite::eHardware
+ : BreakpointSite::eExternal);
+ }
+
+ return joined;
+}
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
index 7c2877fa71d49..63215f3e612c8 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
@@ -170,6 +170,9 @@ class ProcessGDBRemote : public Process,
// Process Breakpoints
Status EnableBreakpointSite(BreakpointSite *bp_site) override;
+ llvm::Error UpdateBreakpointSites(
+ const BreakpointSiteToActionMap &site_to_action) override;
+
Status DisableBreakpointSite(BreakpointSite *bp_site) override;
// Process Watchpoints
@@ -462,6 +465,9 @@ class ProcessGDBRemote : public Process,
/// z packet or restoring the original instruction.
llvm::Error DoDisableBreakpointSite(BreakpointSite &bp_site);
+ llvm::Error UpdateBreakpointSitesNotBatched(
+ const BreakpointSiteToActionMap &site_to_action);
+
static bool NewThreadNotifyBreakpointHit(void *baton,
StoppointCallbackContext *context,
lldb::user_id_t break_id,
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index fc93346ec6c67..86ce97c37dad3 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -272,6 +272,7 @@ void Target::CleanupProcess() {
m_breakpoint_list.ClearAllBreakpointSites();
m_internal_breakpoint_list.ClearAllBreakpointSites();
ResetBreakpointHitCounts();
+ llvm::consumeError(m_process_sp->FlushDelayedBreakpoints());
// Disable watchpoints just on the debugger side.
std::unique_lock<std::recursive_mutex> lock;
this->GetWatchpointList().GetListMutex(lock);
diff --git a/lldb/source/Utility/GDBRemote.cpp b/lldb/source/Utility/GDBRemote.cpp
index f987ebcd4f63e..bd322a5e9e540 100644
--- a/lldb/source/Utility/GDBRemote.cpp
+++ b/lldb/source/Utility/GDBRemote.cpp
@@ -24,6 +24,10 @@ StreamGDBRemote::StreamGDBRemote(uint32_t flags, ByteOrder byte_order)
StreamGDBRemote::~StreamGDBRemote() = default;
+int StreamGDBRemote::PutEscapedBytes(llvm::StringRef str) {
+ return PutEscapedBytes(str.data(), str.size());
+}
+
int StreamGDBRemote::PutEscapedBytes(const void *s, size_t src_len) {
int bytes_written = 0;
const uint8_t *src = static_cast<const uint8_t *>(s);
diff --git a/lldb/test/API/functionalities/breakpoint/delayed_breakpoints/TestDelayedBreakpoint.py b/lldb/test/API/functionalities/breakpoint/delayed_breakpoints/TestDelayedBreakpoint.py
index 75d760bd93ee9..0d55e4e03f2e9 100644
--- a/lldb/test/API/functionalities/breakpoint/delayed_breakpoints/TestDelayedBreakpoint.py
+++ b/lldb/test/API/functionalities/breakpoint/delayed_breakpoints/TestDelayedBreakpoint.py
@@ -38,7 +38,10 @@ def test(self):
self.assertNotIn("send packet: $z", log_before_continue)
log_after = log_text.split("AFTER_BPS", 1)[-1].split("AFTER_CONTINUE", 1)[0]
- self.assertIn("send packet: $Z", log_after)
+ if "jMultiBreakpoint+" in lldbutil.get_qsupported_capabilities(self):
+ self.assertIn("send packet: $jMultiBreakpoint", log_after)
+ else:
+ self.assertIn("send packet: $Z", log_after)
def test_eager_breakpoints(self):
self.build()
@@ -65,6 +68,9 @@ def test_eager_breakpoints(self):
.splitlines()
)
breakpoint_lines = [line for line in log if "send packet: $Z" in line]
+ breakpoint_lines += [
+ line for line in log if "send packet: $jMultiBreakpoint" in line
+ ]
breakpoint_lines = "".join(breakpoint_lines)
bp_addresses = [f"{loc.GetLoadAddress():x}" for loc in bp1.locations]
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