Debugger implementation (#13433)

###  DISCLAIMER

> As of 6th March 2025, debugger is still in development. We plan to
merge it behind a staff-only feature flag for staff use only, followed
by non-public release and then finally a public one (akin to how Git
panel release was handled). This is done to ensure the best experience
when it gets released.

### END OF DISCLAIMER 

**The current state of the debugger implementation:**


https://github.com/user-attachments/assets/c4deff07-80dd-4dc6-ad2e-0c252a478fe9


https://github.com/user-attachments/assets/e1ed2345-b750-4bb6-9c97-50961b76904f

----

All the todo's are in the following channel, so it's easier to work on
this together:
https://zed.dev/channel/zed-debugger-11370

If you are on Linux, you can use the following command to join the
channel:
```cli
zed https://zed.dev/channel/zed-debugger-11370 
```

## Current Features

- Collab
  - Breakpoints
    - Sync when you (re)join a project
    - Sync when you add/remove a breakpoint
  - Sync active debug line
  - Stack frames
    - Click on stack frame
      - View variables that belong to the stack frame
      - Visit the source file
    - Restart stack frame (if adapter supports this)
  - Variables
  - Loaded sources
  - Modules
  - Controls
    - Continue
    - Step back
      - Stepping granularity (configurable)
    - Step into
      - Stepping granularity (configurable)
    - Step over
      - Stepping granularity (configurable)
    - Step out
      - Stepping granularity (configurable)
  - Debug console
- Breakpoints
  - Log breakpoints
  - line breakpoints
  - Persistent between zed sessions (configurable)
  - Multi buffer support
  - Toggle disable/enable all breakpoints
- Stack frames
  - Click on stack frame
    - View variables that belong to the stack frame
    - Visit the source file
    - Show collapsed stack frames
  - Restart stack frame (if adapter supports this)
- Loaded sources
  - View all used loaded sources if supported by adapter.
- Modules
  - View all used modules (if adapter supports this)
- Variables
  - Copy value
  - Copy name
  - Copy memory reference
  - Set value (if adapter supports this)
  - keyboard navigation
- Debug Console
  - See logs
  - View output that was sent from debug adapter
    - Output grouping
  - Evaluate code
    - Updates the variable list
    - Auto completion
- If not supported by adapter, we will show auto-completion for existing
variables
- Debug Terminal
- Run custom commands and change env values right inside your Zed
terminal
- Attach to process (if adapter supports this)
  - Process picker
- Controls
  - Continue
  - Step back
    - Stepping granularity (configurable)
  - Step into
    - Stepping granularity (configurable)
  - Step over
    - Stepping granularity (configurable)
  - Step out
    - Stepping granularity (configurable)
  - Disconnect
  - Restart
  - Stop
- Warning when a debug session exited without hitting any breakpoint
- Debug view to see Adapter/RPC log messages
- Testing
  - Fake debug adapter
    - Fake requests & events

---

Release Notes:

- N/A

---------

Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>
Co-authored-by: Anthony Eid <hello@anthonyeid.me>
Co-authored-by: Anthony <anthony@zed.dev>
Co-authored-by: Piotr Osiewicz <peterosiewicz@gmail.com>
Co-authored-by: Piotr <piotr@zed.dev>

crates/project/src/buffer_store.rs

@@ -85,6 +85,10 @@ enum OpenBuffer {
 
 pub enum BufferStoreEvent {
     BufferAdded(Entity<Buffer>),
+    BufferOpened {
+        buffer: Entity<Buffer>,
+        project_path: ProjectPath,
+    },
     SharedBufferClosed(proto::PeerId, BufferId),
     BufferDropped(BufferId),
     BufferChangedFilePath {
@@ -802,6 +806,13 @@ impl BufferStore {
         }
     }
 
+    fn as_local(&self) -> Option<&LocalBufferStore> {
+        match &self.state {
+            BufferStoreState::Local(state) => Some(state),
+            _ => None,
+        }
+    }
+
     fn as_local_mut(&mut self) -> Option<&mut LocalBufferStore> {
         match &mut self.state {
             BufferStoreState::Local(state) => Some(state),
@@ -829,6 +840,11 @@ impl BufferStore {
         cx: &mut Context<Self>,
     ) -> Task<Result<Entity<Buffer>>> {
         if let Some(buffer) = self.get_by_path(&project_path, cx) {
+            cx.emit(BufferStoreEvent::BufferOpened {
+                buffer: buffer.clone(),
+                project_path,
+            });
+
             return Task::ready(Ok(buffer));
         }
 
@@ -852,12 +868,18 @@ impl BufferStore {
                     .insert(
                         cx.spawn(move |this, mut cx| async move {
                             let load_result = load_buffer.await;
-                            this.update(&mut cx, |this, _cx| {
+                            this.update(&mut cx, |this, cx| {
                                 // Record the fact that the buffer is no longer loading.
                                 this.loading_buffers.remove(&project_path);
-                            })
-                            .ok();
-                            load_result.map_err(Arc::new)
+
+                                let buffer = load_result.map_err(Arc::new)?;
+                                cx.emit(BufferStoreEvent::BufferOpened {
+                                    buffer: buffer.clone(),
+                                    project_path,
+                                });
+
+                                Ok(buffer)
+                            })?
                         })
                         .shared(),
                     )
@@ -1147,6 +1169,11 @@ impl BufferStore {
         })
     }
 
+    pub fn buffer_id_for_project_path(&self, project_path: &ProjectPath) -> Option<&BufferId> {
+        self.as_local()
+            .and_then(|state| state.local_buffer_ids_by_path.get(project_path))
+    }
+
     pub fn get_by_path(&self, path: &ProjectPath, cx: &App) -> Option<Entity<Buffer>> {
         self.buffers().find_map(|buffer| {
             let file = File::from_dyn(buffer.read(cx).file())?;