Make Flowistry less annoying when it can't find a file

crates/flowistry_ide/src/plugin.rs

@@ -189,7 +189,7 @@ fn postprocess<T: Serialize>(result: FlowistryResult<T>) -> RustcResult<()> {
       FlowistryError::BuildError => {
         return Err(rustc_errors::ErrorGuaranteed::unchecked_claim_error_was_emitted());
       }
-      FlowistryError::AnalysisError(msg) => Err(msg),
+      e => Err(e),
     },
   };
 
@@ -234,13 +234,17 @@ fn run<A: FlowistryAnalysis, T: ToSpan>(
   callbacks
     .output
     .unwrap()
-    .map_err(|e| FlowistryError::AnalysisError(e.to_string()))
+    .map_err(|e| FlowistryError::AnalysisError {
+      error: e.to_string(),
+    })
 }
 
-#[derive(Debug)]
+#[derive(Debug, Serialize)]
+#[serde(tag = "type")]
 pub enum FlowistryError {
   BuildError,
-  AnalysisError(String),
+  AnalysisError { error: String },
+  FileNotFound,
 }
 
 pub type FlowistryResult<T> = Result<T, FlowistryError>;

crates/flowistry_ide/src/spans.rs

@@ -1,7 +1,7 @@
 use flowistry::source_map::{find_bodies, Range};
 use serde::Serialize;
 
-use crate::plugin::FlowistryResult;
+use crate::plugin::{FlowistryError, FlowistryResult};
 
 #[derive(Serialize)]
 pub struct SpansOutput {
@@ -10,7 +10,7 @@ pub struct SpansOutput {
 
 struct Callbacks {
   filename: String,
-  output: Option<SpansOutput>,
+  output: Option<FlowistryResult<SpansOutput>>,
 }
 
 impl rustc_driver::Callbacks for Callbacks {
@@ -22,25 +22,27 @@ impl rustc_driver::Callbacks for Callbacks {
     queries.global_ctxt().unwrap().take().enter(|tcx| {
       let spans = find_bodies(tcx).into_iter().map(|(span, _)| span);
 
-      let source_map = compiler.session().source_map();
-      let source_file = Range {
-        byte_start: 0,
-        byte_end: 0,
-        char_start: 0,
-        char_end: 0,
-        filename: self.filename.clone(),
-      }
-      .source_file(source_map)
-      .unwrap();
+      self.output = Some((|| {
+        let source_map = compiler.session().source_map();
+        let source_file = Range {
+          byte_start: 0,
+          byte_end: 0,
+          char_start: 0,
+          char_end: 0,
+          filename: self.filename.clone(),
+        }
+        .source_file(source_map)
+        .map_err(|_| FlowistryError::FileNotFound)?;
 
-      let spans = spans
-        .into_iter()
-        .filter(|span| {
-          source_map.lookup_source_file(span.lo()).name_hash == source_file.name_hash
-        })
-        .filter_map(|span| Range::from_span(span, source_map).ok())
-        .collect::<Vec<_>>();
-      self.output = Some(SpansOutput { spans });
+        let spans = spans
+          .into_iter()
+          .filter(|span| {
+            source_map.lookup_source_file(span.lo()).name_hash == source_file.name_hash
+          })
+          .filter_map(|span| Range::from_span(span, source_map).ok())
+          .collect::<Vec<_>>();
+        Ok(SpansOutput { spans })
+      })());
     });
     rustc_driver::Compilation::Stop
   }
@@ -52,5 +54,5 @@ pub fn spans(args: &[String], filename: String) -> FlowistryResult<SpansOutput>
     output: None,
   };
   crate::plugin::run_with_callbacks(args, &mut callbacks)?;
-  Ok(callbacks.output.unwrap())
+  callbacks.output.unwrap()
 }

ide/src/errors.ts

@@ -9,14 +9,17 @@ import { globals } from "./extension";
 import { log, logs } from "./logging";
 
 interface BuildError {
-  type: "build-error";
+  type: "BuildError";
   error: string;
 }
 interface AnalysisError {
-  type: "analysis-error";
+  type: "AnalysisError";
   error: string;
 }
-export type FlowistryError = BuildError | AnalysisError;
+interface FileNotFound {
+  type: "FileNotFound"
+}
+export type FlowistryError = BuildError | AnalysisError | FileNotFound;
 interface FlowistryOutput<T> {
   type: "output";
   value: T;
@@ -134,18 +137,20 @@ ${log_text}`,
   }
 };
 
-export const show_error = async (error: BuildError | AnalysisError) => {
-  if (error.type === "build-error") {
+export const show_error = async (error: FlowistryError) => {
+  if (error.type === "BuildError") {
     await globals.error_pane.show(error.error);
-  } else {
+  } else if (error.type == "AnalysisError") {
     await show_error_dialog(error.error);
+  } else if (error.type == "FileNotFound") {
+    // should not reach here
   }
 };
 
 export let hide_error = () => globals.error_pane.hide();
 
 export async function last_error(context: vscode.ExtensionContext) {
   let error = context.workspaceState.get("err_log") as string;
-  let flowistry_err: BuildError = { type: "build-error", error };
+  let flowistry_err: BuildError = { type: "BuildError", error };
   await show_error(flowistry_err);
 }

ide/src/focus.ts

@@ -253,7 +253,7 @@ let valid_document = (doc: vscode.TextDocument): boolean => {
  */
 export class FocusMode {
   mode: StatusBarState = "idle";
-  state: Map<string, FocusDocumentState> = new Map();
+  state: Map<string, FocusDocumentState | "notfound"> = new Map();
 
   doc_save_callback?: vscode.Disposable;
   doc_edit_callback?: vscode.Disposable;
@@ -313,7 +313,7 @@ export class FocusMode {
   private get_doc_state = async (
     editor: vscode.TextEditor
   ): Promise<FocusDocumentState | null> => {
-    if (this.mode !== "active") {
+    if (this.mode !== "active" && this.mode !== "notfound") {
       return null;
     }
 
@@ -326,13 +326,23 @@ export class FocusMode {
       if (is_ok(doc_state_res)) {
         this.state.set(filename, doc_state_res.value);
       } else {
-        await show_error(doc_state_res);
-        this.set_mode("error");
-        return null;
+        if (doc_state_res.type == "FileNotFound") {
+         this.state.set(filename, "notfound");
+        } else {
+          await show_error(doc_state_res);
+          this.set_mode("error");
+          return null;  
+        }        
       }
     }
 
-    return this.state.get(filename)!;
+    let state = this.state.get(filename)!;
+    if (state == "notfound") {
+      this.set_mode("notfound");
+      return null;
+    } else {
+      return state;
+    }
   };
 
   private handle_analysis_result = async <T>(result: FlowistryResult<T>) => {

ide/src/setup.ts

@@ -7,7 +7,7 @@ import { Readable } from "stream";
 import * as vscode from "vscode";
 
 import { download } from "./download";
-import { FlowistryResult } from "./errors";
+import { FlowistryError, FlowistryResult } from "./errors";
 import { globals } from "./extension";
 import { log } from "./logging";
 
@@ -17,14 +17,8 @@ declare const TOOLCHAIN: {
   components: string[];
 };
 
-// serde-compatible types
-interface Ok<T> {
-  Ok: T;
-}
-interface Err {
-  Err: string;
-}
-type Result<T> = Ok<T> | Err;
+// serde-compatible type
+type Result<T> = { Ok: T } | { Err: FlowistryError };
 
 /* eslint no-undef: "off" */
 const LIBRARY_PATHS: Partial<Record<NodeJS.Platform, string>> = {
@@ -224,7 +218,7 @@ export async function setup(
       context.workspaceState.update("err_log", e);
 
       return {
-        type: "build-error",
+        type: "BuildError",
         error: e,
       };
     }
@@ -238,10 +232,7 @@ export async function setup(
 
     let output_typed: Result<T> = JSON.parse(output);
     if ("Err" in output_typed) {
-      return {
-        type: "analysis-error",
-        error: output_typed.Err,
-      };
+      return output_typed.Err;
     } else {
       return {
         type: "output",

ide/src/status_bar.ts

@@ -5,13 +5,15 @@ export type StatusBarState =
   | "unsaved"
   | "idle"
   | "error"
-  | "loading";
+  | "loading"
+  | "notfound";
 
 interface StatusBarConfig {
   foreground: string;
   background: string;
   icon?: string;
   command: string;
+  tooltip?: string;
 }
 
 const config_for_state: Record<StatusBarState, StatusBarConfig> = {
@@ -44,6 +46,13 @@ const config_for_state: Record<StatusBarState, StatusBarConfig> = {
     icon: "sync~spin",
     command: "flowistry.focus",
   },
+  notfound: {
+    foreground: "statusBarItem.foreground",
+    background: "statusBarItem.background",
+    icon: "question",
+    command: "flowistry.focus",
+    tooltip: "Flowistry could not get Cargo to find this file (this is probably a Flowistry bug)"
+  },
 };
 
 export class StatusBar {
@@ -68,5 +77,6 @@ export class StatusBar {
     this.bar_item.backgroundColor = new vscode.ThemeColor(config.background);
     this.bar_item.text = `$(${config.icon}) flowistry`;
     this.bar_item.command = config.command;
+    this.bar_item.tooltip = config.tooltip;
   }
 }