[lldb-dap] wrong breakpoint verified status

[nd-work]

To reproduce, debug the following program with lldb-dap from Xcode 26.0.1 and one breakpoint:

#include <iostream>

int main() {
  std::cout << "ok\n";
  std::cout << "ok\n"; // break
  std::cout << "ok\n";
}

Lldb dap first replies that the breakpoint is verified:

1759217371.887020111 <-- 
Content-Length: 294
{
  "body": {
    "breakpoints": [
      {
        "column": 13,
        "id": 1,
        "instructionReference": "0x100000CF8",
        "line": 5,
        "source": {
          "name": "main.cpp",
          "path": "/Users/dmitry.neverov/w/a/CLionProjects/playgroundCpp/main.cpp"
        },
        "verified": true
      }
    ]
  },
  "command": "setBreakpoints",
  "request_seq": 3,
  "seq": 0,
  "success": true,
  "type": "response"
}

and then later sends an event where the breakpoint is not verified:

1759217371.916330099 <-- 
Content-Length: 177

{
  "body": {
    "breakpoint": {
      "column": 13,
      "id": 1,
      "instructionReference": "0xFFFFFFFFFFFFFFFF",
      "line": 5,
      "verified": false
    },
    "reason": "changed"
  },
  "event": "breakpoint",
  "seq": 0,
  "type": "event"
}

The program successfully stops at the breakpoint, so the verified flag in the breakpoint is wrong.

lldb_dap.log

[llvmbot]

@llvm/issue-subscribers-lldb-dap

Author: None (nd-work)

To reproduce, debug the following program with lldb-dap from Xcode 26.0.1 and one breakpoint:

#include <iostream>

int main() {
  std::cout << "ok\n";
  std::cout << "ok\n"; // break
  std::cout << "ok\n";
}

Lldb dap first replies that the breakpoint is verified:

1759217371.887020111 <-- 
Content-Length: 294
{
  "body": {
    "breakpoints": [
      {
        "column": 13,
        "id": 1,
        "instructionReference": "0x100000CF8",
        "line": 5,
        "source": {
          "name": "main.cpp",
          "path": "/Users/dmitry.neverov/w/a/CLionProjects/playgroundCpp/main.cpp"
        },
        "verified": true
      }
    ]
  },
  "command": "setBreakpoints",
  "request_seq": 3,
  "seq": 0,
  "success": true,
  "type": "response"
}

and then later sends an event where the breakpoint is not verified:

1759217371.916330099 <-- 
Content-Length: 177

{
  "body": {
    "breakpoint": {
      "column": 13,
      "id": 1,
      "instructionReference": "0xFFFFFFFFFFFFFFFF",
      "line": 5,
      "verified": false
    },
    "reason": "changed"
  },
  "event": "breakpoint",
  "seq": 0,
  "type": "event"
}

The program successfully stops at the breakpoint, so the verified flag in the breakpoint is wrong.

lldb_dap.log

[walter-erquinigo]

does this cause any glitches in the UI?

[nd-work]

Yes, CLion shows unverified breakpoints in a special way:

Usually they look like this:

[JDevlieghere]

This sounds like #112629 which was fixed by #129589. The PR description explains what's going on here:

On macOS, breakpoints are briefly unresolved between process launch and when the dynamic loader has informed us about the loaded libraries. This information was being forwarded by lldb-dap, but only partially. In the event handler, we were listening for the LocationsAdded and LocationsRemoved breakpoint events. For the scenario described above, the latter would trigger and we'd send an event reporting the breakpoint as unresolved. The problem is that when the breakpoint location is resolved again, you receive a LocationsResolved event, not a LocationsAdded event. As a result, the breakpoint would continue to show up as unresolved in the DAP client.

That fix is part of lldb-dap shipping with Xcode 26 so I wouldn't expect this to show up there.

A first good step would be figuring out if this is also happening with a recent build from llvm.org to rule out it's a different issue or something that regressed.