Implement Debugger.getPossibleBreakpoints (#2067)#2067
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…#2066) Summary: NOTE: This is the minimum fix for fixing React Native compatibility with [vscode-js-debug](https://github.com/microsoft/vscode-js-debug). D109301771 continues by implementing this method fully. **Motivation**: CDP spec / VS Code debugger compatibility. `Debugger.getPossibleBreakpoints` is a gap in our Chrome DevTools Protocol coverage. To date, this hasn't been load bearing for our Chrome DevTools frontend fork in React Native DevTools. **However**, in other clients such as VS Code, not implementing this method breaks debugging against Hermes targets, since these clients expect at minimum a spec compliant CDP response (currently `-32601 method not found`). **This diff** Handle `Debugger.getPossibleBreakpoints` in Hermes as a spec-compliant stub endpoint, unconditionally returning an empty result (`{ locations: [] }`). - This is valid / equivalent to today's behaviour — setting a breakpoint applies to the whole line (no inner granularity). - A stub is how Expo and Radon IDE handle this issue today, e.g. `VscodeDebuggerGetPossibleBreakpointsHandler` in Expo CLI. https://github.com/expo/expo/blob/cc3f274fa0bb56aa0aa85ef68d78f1348e40d7f8/packages/%40expo/cli/src/start/server/metro/debugging/messageHandlers/VscodeDebuggerGetPossibleBreakpoints.ts#L17-L22 **This change alone is enough to stop VS Code erroring.** Computing breakpoint locations is a bit more involved (and notably might be blocked by the newer Babel transform profile rollout in RN), and is implemented separately in the next diff. **Changes** - Add `Debugger.getPossibleBreakpoints` to the CDP message-type roots (`cdp/tools/message_types.txt`) and regenerate `MessageTypes.{h,cpp}` (the pinned upstream protocol already defines the request/response and `BreakLocation` types). - Dispatch the method in `CDPAgent` to a new `DebuggerDomainAgent::getPossibleBreakpoints` that unconditionally returns `{ locations: [] }`. Differential Revision: D109439195
Summary:
**Motivation**: CDP spec / VS Code debugging compatibility.
Implements the `Debugger.getPossibleBreakpoints` CDP method so debug clients such as the React Native DevTools Sources panel and VS Code can discover and indicate valid breakpoint positions within a source range.
We walk the existing Hermes bytecode debug info, so no new compiler work is required.
**Changes**
- `DebugInfo::getAllLocationsForRange` enumerates every source location within a 1-based, half-open line/column range, mirroring the region scan in `getAddressForLocation` but collecting all matches instead of a single best one.
- `vm::Debugger::getPossibleBreakpoints` resolves the script's `RuntimeModule`/`DebugInfo`, classifies each location's real opcode as a debugger statement, call, or return via `getRealOpCode`/`isCallType`, then reduces the per-instruction debug info to one location per source statement (plus every call, return, and `debugger` location) and de-duplicates by source position. This statement-level granularity matches V8's `getPossibleBreakpoints` and Hermes' own stepper, which stops at the first instruction of each distinct statement; without it the one-entry-per-instruction debug info surfaces a candidate at nearly every token.
- Exposes the capability on the public `debugger::Debugger` API via a new `BreakLocation`/`BreakLocationType` value type.
- Wires it into the CDP layer: adds the method to the message-type roots and regenerates `MessageTypes` (the pinned upstream protocol already defines `getPossibleBreakpoints` and `BreakLocation`), dispatches it in `CDPAgent`, and handles it in `DebuggerDomainAgent` with the CDP/Hermes 0-based to 1-based conversion and a 1000-location cap matching V8's `kMaxNumBreakpoints`.
**Behaviour**
- Unknown `scriptId` returns CDP error `-32000` "No script with id"; a `start`/`end` on different scripts or with `start` after `end` returns "Invalid range"; an empty range returns `{ locations: [] }`.
- `restrictToFunction` is accepted but ignored for now, and lazily-compiled functions are not yet enumerated.
Differential Revision: D109301771
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Summary:
Motivation: CDP spec / VS Code debugging compatibility.
Implements the
Debugger.getPossibleBreakpointsCDP method so debug clients such as the React Native DevTools Sources panel and VS Code can discover and indicate valid breakpoint positions within a source range.We walk the existing Hermes bytecode debug info, so no new compiler work is required.
Changes
DebugInfo::getAllLocationsForRangeenumerates every source location within a 1-based, half-open line/column range, mirroring the region scan ingetAddressForLocationbut collecting all matches instead of a single best one.vm::Debugger::getPossibleBreakpointsresolves the script'sRuntimeModule/DebugInfo, classifies each location's real opcode as a debugger statement, call, or return viagetRealOpCode/isCallType, then reduces the per-instruction debug info to one location per source statement (plus every call, return, anddebuggerlocation) and de-duplicates by source position. This statement-level granularity matches V8'sgetPossibleBreakpointsand Hermes' own stepper, which stops at the first instruction of each distinct statement; without it the one-entry-per-instruction debug info surfaces a candidate at nearly every token.debugger::DebuggerAPI via a newBreakLocation/BreakLocationTypevalue type.MessageTypes(the pinned upstream protocol already definesgetPossibleBreakpointsandBreakLocation), dispatches it inCDPAgent, and handles it inDebuggerDomainAgentwith the CDP/Hermes 0-based to 1-based conversion and a 1000-location cap matching V8'skMaxNumBreakpoints.Behaviour
scriptIdreturns CDP error-32000"No script with id"; astart/endon different scripts or withstartafterendreturns "Invalid range"; an empty range returns{ locations: [] }.restrictToFunctionis accepted but ignored for now, and lazily-compiled functions are not yet enumerated.Differential Revision: D109301771