Merge pull request #807 from posit-dev/feature/debug-completions

Inject debug environment in search path completions

Author: lionel-

crates/ark/src/interface.rs

@@ -255,6 +255,11 @@ pub struct RMain {
     /// The stack of frames we saw the last time we stopped. Used as a mostly
     /// reliable indication of whether we moved since last time.
     debug_last_stack: Vec<FrameInfoId>,
+
+    /// Current topmost environment on the stack while waiting for input in the
+    /// debugger. This is `Some()` only when R is idle and in a `browser()`
+    /// prompt.
+    debug_env: Option<RObject>,
 }
 
 /// Represents the currently active execution request from the frontend. It
@@ -588,6 +593,7 @@ impl RMain {
             captured_output: String::new(),
             debug_preserve_focus: false,
             debug_last_stack: vec![],
+            debug_env: None,
         }
     }
 
@@ -774,6 +780,13 @@ impl RMain {
         if info.browser {
             match self.dap.stack_info() {
                 Ok(stack) => {
+                    if let Some(frame) = stack.first() {
+                        if let Some(ref env) = frame.environment {
+                            // This is reset on exit in the cleanup phase, see `r_read_console()`
+                            self.debug_env = Some(env.get().clone());
+                        }
+                    }
+
                     // Figure out whether we changed location since last time,
                     // e.g. because the user evaluated an expression that hit
                     // another breakpoint. In that case we do want to move
@@ -961,6 +974,11 @@ impl RMain {
         };
     }
 
+    fn read_console_cleanup(&mut self) {
+        // The debug environment is only valid while R is idle
+        self.debug_env = None;
+    }
+
     /// Returns:
     /// - `None` if we should fall through to the event loop to wait for more user input
     /// - `Some(ConsoleResult)` if we should immediately exit `read_console()`
@@ -2054,6 +2072,11 @@ impl RMain {
             StdInRpcReply::Interrupt => Ok(RObject::null()),
         }
     }
+
+    #[cfg(not(test))] // Avoid warnings in unit test
+    pub(crate) fn debug_env(&self) -> Option<RObject> {
+        self.debug_env.clone()
+    }
 }
 
 /// Report an incomplete request to the frontend
@@ -2124,6 +2147,7 @@ pub extern "C-unwind" fn r_read_console(
 ) -> i32 {
     let main = RMain::get_mut();
     let result = r_sandbox(|| main.read_console(prompt, buf, buflen, hist));
+    main.read_console_cleanup();
 
     let result = unwrap!(result, Err(err) => {
         panic!("Unexpected longjump while reading console: {err:?}");

crates/ark/src/lsp/completions/sources/composite/search_path.rs

@@ -58,14 +58,25 @@ fn completions_from_search_path(
 
     unsafe {
         // Iterate through environments starting from the global environment.
-        let mut envir = R_GlobalEnv;
+        let mut env = R_GlobalEnv;
+
+        // If we're waiting for input in `read_console()` with a debugger
+        // prompt, start from current environment
+        #[cfg(not(test))] // Unit tests do not have an `RMain`
+        {
+            use crate::interface::RMain;
+            if let Some(debug_env) = &RMain::get().debug_env() {
+                // Mem-Safety: Object protected by `RMain` for the duration of the `r_task()`
+                env = debug_env.sexp;
+            }
+        }
 
-        while envir != R_EmptyEnv {
-            let is_pkg_env = r_env_is_pkg_env(envir);
+        while env != R_EmptyEnv {
+            let is_pkg_env = r_env_is_pkg_env(env);
 
             // Get package environment name, if there is one
             let name = if is_pkg_env {
-                let name = RObject::from(r_pkg_env_name(envir));
+                let name = RObject::from(r_pkg_env_name(env));
                 let name = String::try_from(name)?;
                 Some(name)
             } else {
@@ -84,7 +95,7 @@ fn completions_from_search_path(
             };
 
             // List symbols in the environment.
-            let symbols = R_lsInternal(envir, 1);
+            let symbols = R_lsInternal(env, 1);
 
             // Create completion items for each.
             let vector = CharacterVector::new(symbols)?;
@@ -103,9 +114,9 @@ fn completions_from_search_path(
                 // Add the completion item.
                 match completion_item_from_symbol(
                     symbol,
-                    envir,
+                    env,
                     name,
-                    promise_strategy.clone(),
+                    promise_strategy,
                     parameter_hints,
                 ) {
                     Ok(item) => completions.push(item),
@@ -118,7 +129,7 @@ fn completions_from_search_path(
             }
 
             // Get the next environment.
-            envir = ENCLOS(envir);
+            env = ENCLOS(env);
         }
 
         // Include installed packages as well.

crates/ark/src/lsp/completions/types.rs

@@ -54,7 +54,7 @@ pub(super) enum CompletionData {
     Unknown,
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Copy, Clone, Debug, PartialEq)]
 pub(crate) enum PromiseStrategy {
     Simple,
     Force,