[lldb-dap] add debugAdapterExecutable property to launch configuration

[matthewbastien]

The Swift extension for VS Code requires that the lldb-dap executable come from the Swift toolchain which may or may not be configured in PATH. At the moment, this can be configured via LLDB DAP's extension settings, but experience has shown that modifying other extensions' settings on behalf of the user (especially those subject to change whenever a new toolchain is selected) causes issues. Instead, it would be easier to have this configurable in the launch configuration and let the Swift extension (or any other extension that wanted to, really) configure the path to lldb-dap that way. This allows the Swift extension to have its own launch configuration type that delegates to the LLDB DAP extension in order to provide a more seamless debugging experience for Swift executables.

This PR adds a new property to the launch configuration object called debugAdapterExecutable which allows overriding the lldb-dap executable path for a specific debug session.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Matthew Bastien (matthewbastien)

Changes

The Swift extension for VS Code requires that the lldb-dap executable come from the Swift toolchain which may or may not be configured in PATH. At the moment, this can be configured via LLDB DAP's extension settings, but experience has shown that modifying other extensions' settings on behalf of the user (especially those subject to change whenever a new toolchain is selected) causes issues. Instead, it would be easier to have this configurable in the launch configuration and let the Swift extension (or any other extension that wanted to, really) configure the path to lldb-dap that way. This allows the Swift extension to have its own launch configuration type that delegates to the LLDB DAP extension in order to provide a more seamless debugging experience for Swift executables.

This PR adds a new property to the launch configuration object called debugAdapterExecutable which allows overriding the lldb-dap executable path for a specific debug session.

---

Full diff: https://github.com/llvm/llvm-project/pull/126803.diff

2 Files Affected:

• (modified) lldb/tools/lldb-dap/package.json (+5-1)
• (modified) lldb/tools/lldb-dap/src-ts/debug-adapter-factory.ts (+7-2)

diff --git a/lldb/tools/lldb-dap/package.json b/lldb/tools/lldb-dap/package.json
index e866af0602d70..fb4a828795041 100644
--- a/lldb/tools/lldb-dap/package.json
+++ b/lldb/tools/lldb-dap/package.json
@@ -86,7 +86,7 @@
           "default": {},
           "description": "The environment of the lldb-dap process.",
           "additionalProperties": {
-             "type": "string"
+            "type": "string"
           }
         }
       }
@@ -152,6 +152,10 @@
               "program"
             ],
             "properties": {
+              "debugAdapterExecutable": {
+                "type": "string",
+                "markdownDescription": "The LLDB debug adapter executable to use. Either an absolute path or the name of a debug adapter executable available on the `PATH`."
+              },
               "program": {
                 "type": "string",
                 "description": "Path to the program to debug."
diff --git a/lldb/tools/lldb-dap/src-ts/debug-adapter-factory.ts b/lldb/tools/lldb-dap/src-ts/debug-adapter-factory.ts
index 55c2f3e9f7deb..e1c6bd4fd4300 100644
--- a/lldb/tools/lldb-dap/src-ts/debug-adapter-factory.ts
+++ b/lldb/tools/lldb-dap/src-ts/debug-adapter-factory.ts
@@ -67,12 +67,17 @@ async function findDAPExecutable(): Promise<string | undefined> {
 async function getDAPExecutable(
   session: vscode.DebugSession,
 ): Promise<string | undefined> {
+  // Check if the executable was provided in the launch configuration.
+  const launchConfigPath = session.configuration["debugAdapterExecutable"];
+  if (typeof launchConfigPath === "string" && launchConfigPath.length !== 0) {
+    return launchConfigPath;
+  }
+
+  // Check if the executable was provided in the extension's configuration.
   const config = vscode.workspace.getConfiguration(
     "lldb-dap",
     session.workspaceFolder,
   );
-
-  // Prefer the explicitly specified path in the extension's configuration.
   const configPath = config.get<string>("executable-path");
   if (configPath && configPath.length !== 0) {
     return configPath;

[vogelsgesang]

@tedwoodward does this PR also address your request in #123842, or did you have something else in mind?

[JDevlieghere]

LGTM!

@tedwoodward does this PR also address your request in #123842, or did you have something else in mind?

I was thinking the same thing. I'm pretty sure this is doing exactly what Ted's asking for.