Enable nil diagnostics for multiple files

crates/nil/src/main.rs

@@ -1,7 +1,14 @@
+use anyhow::anyhow;
 use anyhow::{Context, Result};
 use argh::FromArgs;
+use codespan_reporting::diagnostic::Severity;
 use codespan_reporting::term::termcolor::WriteColor;
-use ide::{AnalysisHost, Severity};
+use ide::AnalysisHost;
+use ide::Change;
+use ide::FileId;
+use ide::FileSet;
+use ide::SourceRoot;
+use ide::VfsPath;
 use std::io::IsTerminal;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
@@ -39,15 +46,15 @@ enum Subcommand {
 
 #[derive(Debug, FromArgs)]
 #[argh(subcommand, name = "diagnostics")]
-/// Check and print diagnostics for a file.
+/// Check and print diagnostics for Nix files.
 /// Exit with non-zero code if there are any diagnostics. (`1` for errors, `2` if only warnings)
 /// WARNING: The output format is for human and should not be relied on.
 struct DiagnosticsArgs {
-    /// nix file to check, or read from stdin for `-`.
+    /// nix files to check, or read from stdin for `-`.
     /// NB. You need `--` before `-` for paths starting with `-`,
     /// to disambiguous it from flags.
     #[argh(positional)]
-    path: PathBuf,
+    paths: Vec<PathBuf>,
 }
 
 #[derive(Debug, FromArgs)]
@@ -111,32 +118,12 @@ fn main() {
 }
 
 fn main_diagnostics(args: DiagnosticsArgs) {
-    use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
-
-    let ret = (|| -> Result<Option<Severity>> {
-        let path = &*args.path;
-
-        let src = if path.as_os_str() == "-" {
-            io::read_to_string(io::stdin().lock()).context("Failed to read from stdin")?
-        } else {
-            fs::read_to_string(path).context("Failed to read file")?
-        };
-
-        let (analysis, file) = AnalysisHost::new_single_file(&src);
-        let diags = analysis
-            .snapshot()
-            .diagnostics(file)
-            .expect("No cancellation");
+    let ret = diagnostics_for_files(args.paths);
 
-        let mut writer = StandardStream::stdout(ColorChoice::Auto);
-        emit_diagnostics(path, &src, &mut writer, &mut diags.iter().cloned())?;
-
-        Ok(diags.iter().map(|diag| diag.severity()).max())
-    })();
     match ret {
         Ok(None) => process::exit(0),
         Ok(Some(max_severity)) => {
-            if max_severity > Severity::Warning {
+            if max_severity > ide::Severity::Warning {
                 process::exit(1)
             } else {
                 process::exit(0)
@@ -149,6 +136,56 @@ fn main_diagnostics(args: DiagnosticsArgs) {
     }
 }
 
+fn diagnostics_for_files(paths: Vec<PathBuf>) -> Result<Option<ide::Severity>> {
+    use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
+    if paths.is_empty() {
+        return Err(anyhow!("No files given"));
+    }
+
+    let mut sources = Vec::new();
+    let mut file_set = FileSet::default();
+    let mut change = Change::default();
+    for (id, path) in paths.iter().enumerate() {
+        let file = FileId(id as u32);
+
+        let src = if path.as_os_str() == "-" {
+            io::read_to_string(io::stdin().lock()).context("Failed to read from stdin")?
+        } else {
+            fs::read_to_string(path).context("Failed to read file")?
+        };
+
+        let src: Arc<str> = src.into();
+        sources.push((file, path, src.clone()));
+
+        change.change_file(file, src);
+        file_set.insert(file, VfsPath::new(path));
+    }
+
+    change.set_roots(vec![SourceRoot::new_local(file_set, None)]);
+
+    let mut analysis = AnalysisHost::new();
+    analysis.apply_change(change);
+
+    let snapshot = analysis.snapshot();
+
+    let mut writer = StandardStream::stdout(ColorChoice::Auto);
+    let mut max_severity = None;
+    for (id, path, src) in sources {
+        let diagnostics = snapshot.diagnostics(id).expect("No cancellation");
+        emit_diagnostics(path, &src, &mut writer, &mut diagnostics.iter().cloned())?;
+
+        max_severity = std::cmp::max(
+            max_severity,
+            diagnostics
+                .iter()
+                .map(|diagnostic| diagnostic.severity())
+                .max(),
+        );
+    }
+
+    Ok(max_severity)
+}
+
 fn main_parse(args: ParseArgs) {
     use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
 
@@ -255,7 +292,7 @@ fn emit_diagnostics(
     writer: &mut dyn WriteColor,
     diags: &mut dyn Iterator<Item = ide::Diagnostic>,
 ) -> Result<()> {
-    use codespan_reporting::diagnostic::{Diagnostic, Label, Severity};
+    use codespan_reporting::diagnostic::{Diagnostic, Label};
     use codespan_reporting::files::SimpleFiles;
     use codespan_reporting::term;