dap_adapters: add gdb

.zed/debug.json

@@ -5,5 +5,15 @@
     "program": "$ZED_WORKTREE_ROOT/target/debug/zed",
     "request": "launch",
     "cwd": "$ZED_WORKTREE_ROOT"
+  },
+  {
+    "label": "Debug Zed with GDB",
+    "adapter": "gdb",
+    "program": "$ZED_WORKTREE_ROOT/target/debug/zed",
+    "request": "launch",
+    "cwd": "$ZED_WORKTREE_ROOT",
+    "initialize_args": {
+      "stopAtBeginningOfMainSubprogram": true
+    }
   }
 ]

crates/dap_adapters/src/dap_adapters.rs

@@ -1,4 +1,5 @@
 mod custom;
+mod gdb;
 mod go;
 mod javascript;
 mod lldb;
@@ -12,6 +13,7 @@ use dap::adapters::{
     self, AdapterVersion, DapDelegate, DebugAdapter, DebugAdapterBinary, DebugAdapterName,
     GithubRepo,
 };
+use gdb::GdbDebugAdapter;
 use go::GoDebugAdapter;
 use javascript::JsDebugAdapter;
 use lldb::LldbDebugAdapter;
@@ -33,5 +35,6 @@ pub async fn build_adapter(kind: &DebugAdapterKind) -> Result<Box<dyn DebugAdapt
         }
         DebugAdapterKind::Lldb => Ok(Box::new(LldbDebugAdapter::new())),
         DebugAdapterKind::Go(host) => Ok(Box::new(GoDebugAdapter::new(host).await?)),
+        DebugAdapterKind::Gdb => Ok(Box::new(GdbDebugAdapter::new())),
     }
 }

crates/dap_adapters/src/gdb.rs

@@ -0,0 +1,85 @@
+use std::ffi::OsStr;
+
+use anyhow::Result;
+use async_trait::async_trait;
+use dap::transport::{StdioTransport, Transport};
+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())
+    }
+
+    fn transport(&self) -> Box<dyn Transport> {
+        Box::new(StdioTransport::new())
+    }
+
+    async fn get_binary(
+        &self,
+        delegate: &dyn DapDelegate,
+        config: &DebugAdapterConfig,
+        user_installed_path: Option<PathBuf>,
+    ) -> 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(),
+            version: "1".into(),
+        })
+    }
+
+    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<PathBuf>,
+    ) -> Result<DebugAdapterBinary> {
+        unimplemented!("GDB cannot be installed by Zed (yet)")
+    }
+
+    fn request_args(&self, config: &DebugAdapterConfig) -> Value {
+        json!({"program": config.program, "cwd": config.cwd})
+    }
+}

crates/task/src/debug_format.rs

@@ -73,6 +73,8 @@ pub enum DebugAdapterKind {
     Go(TCPHost),
     /// Use lldb
     Lldb,
+    /// Use GDB's built-in DAP support
+    Gdb,
 }
 
 impl DebugAdapterKind {
@@ -84,6 +86,7 @@ impl DebugAdapterKind {
             Self::Php(_) => "PHP",
             Self::Javascript(_) => "JavaScript",
             Self::Lldb => "LLDB",
+            Self::Gdb => "GDB",
             Self::Go(_) => "Go",
         }
     }