Improve rust-analyzer diagnostics

In my experience the `processing <module>` messages make it harder to search for the actual diagnostics, so remove them and instead print the filename only if there is a diagnostic.

Also allow choosing the minimum severity.

crates/rust-analyzer/src/cli/diagnostics.rs

@@ -9,7 +9,7 @@ use ide::{AnalysisHost, AssistResolveStrategy, Diagnostic, DiagnosticsConfig, Se
 use ide_db::{LineIndexDatabase, base_db::SourceDatabase};
 use load_cargo::{LoadCargoConfig, ProcMacroServerChoice, load_workspace_at};
 
-use crate::cli::flags;
+use crate::cli::{flags, progress_report::ProgressReport};
 
 impl flags::Diagnostics {
     pub fn run(self) -> anyhow::Result<()> {
@@ -50,23 +50,26 @@ impl flags::Diagnostics {
 
         let mut found_error = false;
         let mut visited_files = FxHashSet::default();
+        let min_severity = self.severity.unwrap_or(flags::Severity::Weak);
 
-        let work = all_modules(db).into_iter().filter(|module| {
-            let file_id = module.definition_source_file_id(db).original_file(db);
-            let source_root = db.file_source_root(file_id.file_id(db)).source_root_id(db);
-            let source_root = db.source_root(source_root).source_root(db);
-            !source_root.is_library
-        });
+        let work = all_modules(db)
+            .into_iter()
+            .filter(|module| {
+                let file_id = module.definition_source_file_id(db).original_file(db);
+                let source_root = db.file_source_root(file_id.file_id(db)).source_root_id(db);
+                let source_root = db.source_root(source_root).source_root(db);
+                !source_root.is_library
+            })
+            .collect::<Vec<_>>();
 
+        let mut bar = ProgressReport::new(work.len());
         for module in work {
             let file_id = module.definition_source_file_id(db).original_file(db);
             if !visited_files.contains(&file_id) {
+                let message = format!("processing {}", _vfs.file_path(file_id.file_id(db)));
+                bar.set_message(move || message.clone());
                 let crate_name =
                     module.krate().display_name(db).as_deref().unwrap_or(&sym::unknown).to_owned();
-                println!(
-                    "processing crate: {crate_name}, module: {}",
-                    _vfs.file_path(file_id.file_id(db))
-                );
                 for diagnostic in analysis
                     .full_diagnostics(
                         &DiagnosticsConfig::test_sample(),
@@ -75,6 +78,16 @@ impl flags::Diagnostics {
                     )
                     .unwrap()
                 {
+                    let severity = match diagnostic.severity {
+                        Severity::Error => flags::Severity::Error,
+                        Severity::Warning => flags::Severity::Warning,
+                        Severity::WeakWarning => flags::Severity::Weak,
+                        Severity::Allow => continue,
+                    };
+                    if severity < min_severity {
+                        continue;
+                    }
+
                     if matches!(diagnostic.severity, Severity::Error) {
                         found_error = true;
                     }
@@ -83,12 +96,17 @@ impl flags::Diagnostics {
                     let line_index = db.line_index(range.file_id);
                     let start = line_index.line_col(range.range.start());
                     let end = line_index.line_col(range.range.end());
-                    println!("{severity:?} {code:?} from {start:?} to {end:?}: {message}");
+                    bar.println(format!(
+                        "at crate {crate_name}, file {}: {severity:?} {code:?} from {start:?} to {end:?}: {message}",
+                        _vfs.file_path(file_id.file_id(db))
+                    ));
                 }
 
                 visited_files.insert(file_id);
             }
+            bar.inc(1);
         }
+        bar.finish_and_clear();
 
         println!();
         println!("diagnostic scan complete");

crates/rust-analyzer/src/cli/flags.rs

@@ -124,6 +124,9 @@ xflags::xflags! {
             optional --disable-proc-macros
             /// Run the proc-macro-srv binary at the specified path.
             optional --proc-macro-srv path: PathBuf
+
+            /// The minimum severity.
+            optional --severity severity: Severity
         }
 
         /// Report unresolved references
@@ -281,6 +284,7 @@ pub struct Diagnostics {
     pub disable_build_scripts: bool,
     pub disable_proc_macros: bool,
     pub proc_macro_srv: Option<PathBuf>,
+    pub severity: Option<Severity>,
 }
 
 #[derive(Debug)]
@@ -376,3 +380,23 @@ impl FromStr for OutputFormat {
         }
     }
 }
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Severity {
+    Weak,
+    Warning,
+    Error,
+}
+
+impl FromStr for Severity {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match &*s.to_ascii_lowercase() {
+            "weak" => Ok(Self::Weak),
+            "warning" => Ok(Self::Warning),
+            "error" => Ok(Self::Error),
+            _ => Err(format!("unknown severity `{s}`")),
+        }
+    }
+}