[lldb-dap][NFC] Add Breakpoint struct to share common logic. (#80753)

This adds a layer between `SounceBreakpoint`/`FunctionBreakpoint` and
`BreakpointBase` to have better separation and encapsulation so we are
not directly operating on `SBBreakpoint`.

I basically moved the `SBBreakpoint` and the methods that requires it
from `BreakpointBase` to `Breakpoint`. This allows adding support for
data watchpoint easier by sharing the logic inside `BreakpointBase`.

Author: ZequanWu

lldb/tools/lldb-dap/Breakpoint.cpp

@@ -0,0 +1,76 @@
+//===-- Breakpoint.cpp ----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Breakpoint.h"
+#include "DAP.h"
+#include "JSONUtils.h"
+#include "llvm/ADT/StringExtras.h"
+
+using namespace lldb_dap;
+
+void Breakpoint::SetCondition() { bp.SetCondition(condition.c_str()); }
+
+void Breakpoint::SetHitCondition() {
+  uint64_t hitCount = 0;
+  if (llvm::to_integer(hitCondition, hitCount))
+    bp.SetIgnoreCount(hitCount - 1);
+}
+
+void Breakpoint::CreateJsonObject(llvm::json::Object &object) {
+  // Each breakpoint location is treated as a separate breakpoint for VS code.
+  // They don't have the notion of a single breakpoint with multiple locations.
+  if (!bp.IsValid())
+    return;
+  object.try_emplace("verified", bp.GetNumResolvedLocations() > 0);
+  object.try_emplace("id", bp.GetID());
+  // VS Code DAP doesn't currently allow one breakpoint to have multiple
+  // locations so we just report the first one. If we report all locations
+  // then the IDE starts showing the wrong line numbers and locations for
+  // other source file and line breakpoints in the same file.
+
+  // Below we search for the first resolved location in a breakpoint and report
+  // this as the breakpoint location since it will have a complete location
+  // that is at least loaded in the current process.
+  lldb::SBBreakpointLocation bp_loc;
+  const auto num_locs = bp.GetNumLocations();
+  for (size_t i = 0; i < num_locs; ++i) {
+    bp_loc = bp.GetLocationAtIndex(i);
+    if (bp_loc.IsResolved())
+      break;
+  }
+  // If not locations are resolved, use the first location.
+  if (!bp_loc.IsResolved())
+    bp_loc = bp.GetLocationAtIndex(0);
+  auto bp_addr = bp_loc.GetAddress();
+
+  if (bp_addr.IsValid()) {
+    std::string formatted_addr =
+        "0x" + llvm::utohexstr(bp_addr.GetLoadAddress(g_dap.target));
+    object.try_emplace("instructionReference", formatted_addr);
+    auto line_entry = bp_addr.GetLineEntry();
+    const auto line = line_entry.GetLine();
+    if (line != UINT32_MAX)
+      object.try_emplace("line", line);
+    const auto column = line_entry.GetColumn();
+    if (column != 0)
+      object.try_emplace("column", column);
+    object.try_emplace("source", CreateSource(line_entry));
+  }
+}
+
+bool Breakpoint::MatchesName(const char *name) { return bp.MatchesName(name); }
+
+void Breakpoint::SetBreakpoint() {
+  // See comments in BreakpointBase::GetBreakpointLabel() for details of why
+  // we add a label to our breakpoints.
+  bp.AddName(GetBreakpointLabel());
+  if (!condition.empty())
+    SetCondition();
+  if (!hitCondition.empty())
+    SetHitCondition();
+}

lldb/tools/lldb-dap/Breakpoint.h

@@ -0,0 +1,33 @@
+//===-- Breakpoint.h --------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_TOOLS_LLDB_DAP_BREAKPOINT_H
+#define LLDB_TOOLS_LLDB_DAP_BREAKPOINT_H
+
+#include "BreakpointBase.h"
+
+namespace lldb_dap {
+
+struct Breakpoint : public BreakpointBase {
+  // The LLDB breakpoint associated wit this source breakpoint
+  lldb::SBBreakpoint bp;
+
+  Breakpoint() = default;
+  Breakpoint(const llvm::json::Object &obj) : BreakpointBase(obj){};
+  Breakpoint(lldb::SBBreakpoint bp) : bp(bp) {}
+
+  void SetCondition() override;
+  void SetHitCondition() override;
+  void CreateJsonObject(llvm::json::Object &object) override;
+
+  bool MatchesName(const char *name);
+  void SetBreakpoint();
+};
+} // namespace lldb_dap
+
+#endif