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/dap_adapters/src/gdb.rs

@@ -0,0 +1,83 @@
+use std::ffi::OsStr;
+
+use anyhow::Result;
+use async_trait::async_trait;
+use gpui::AsyncApp;
+use task::DebugAdapterConfig;
+
+use crate::*;
+
+pub(crate) struct GdbDebugAdapter {}
+
+impl GdbDebugAdapter {
+    const ADAPTER_NAME: &'static str = "gdb";
+
+    pub(crate) fn new() -> Self {
+        GdbDebugAdapter {}
+    }
+}
+
+#[async_trait(?Send)]
+impl DebugAdapter for GdbDebugAdapter {
+    fn name(&self) -> DebugAdapterName {
+        DebugAdapterName(Self::ADAPTER_NAME.into())
+    }
+
+    async fn get_binary(
+        &self,
+        delegate: &dyn DapDelegate,
+        config: &DebugAdapterConfig,
+        user_installed_path: Option<std::path::PathBuf>,
+        _: &mut AsyncApp,
+    ) -> Result<DebugAdapterBinary> {
+        let user_setting_path = user_installed_path
+            .filter(|p| p.exists())
+            .and_then(|p| p.to_str().map(|s| s.to_string()));
+
+        /* GDB implements DAP natively so just need to  */
+        let gdb_path = delegate
+            .which(OsStr::new("gdb"))
+            .and_then(|p| p.to_str().map(|s| s.to_string()))
+            .ok_or(anyhow!("Could not find gdb in path"));
+
+        if gdb_path.is_err() && user_setting_path.is_none() {
+            bail!("Could not find gdb path or it's not installed");
+        }
+
+        let gdb_path = user_setting_path.unwrap_or(gdb_path?);
+
+        Ok(DebugAdapterBinary {
+            command: gdb_path,
+            arguments: Some(vec!["-i=dap".into()]),
+            envs: None,
+            cwd: config.cwd.clone(),
+            connection: None,
+        })
+    }
+
+    async fn install_binary(
+        &self,
+        _version: AdapterVersion,
+        _delegate: &dyn DapDelegate,
+    ) -> Result<()> {
+        unimplemented!("GDB debug adapter cannot be installed by Zed (yet)")
+    }
+
+    async fn fetch_latest_adapter_version(&self, _: &dyn DapDelegate) -> Result<AdapterVersion> {
+        unimplemented!("Fetch latest GDB version not implemented (yet)")
+    }
+
+    async fn get_installed_binary(
+        &self,
+        _: &dyn DapDelegate,
+        _: &DebugAdapterConfig,
+        _: Option<std::path::PathBuf>,
+        _: &mut AsyncApp,
+    ) -> Result<DebugAdapterBinary> {
+        unimplemented!("GDB cannot be installed by Zed (yet)")
+    }
+
+    fn request_args(&self, config: &DebugAdapterConfig) -> Value {
+        json!({"program": config.program, "cwd": config.cwd})
+    }
+}