CLI for diagnostics

Cargo.lock

@@ -64,6 +64,16 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "codespan-reporting"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3538270d33cc669650c4b093848450d380def10c331d38c768e34cac80576e6e"
+dependencies = [
+ "termcolor",
+ "unicode-width",
+]
+
 [[package]]
 name = "countme"
 version = "3.0.1"
@@ -291,6 +301,7 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "argh",
+ "codespan-reporting",
  "crossbeam-channel",
  "ide",
  "indexmap",
@@ -650,6 +661,15 @@ dependencies = [
  "rowan",
 ]
 
+[[package]]
+name = "termcolor"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be55cf8942feac5c765c2c993422806843c9a9a45d4d5c407ad6dd2ea95eb9b6"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "text-size"
 version = "1.1.0"
@@ -768,6 +788,12 @@ version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fdbf052a0783de01e944a6ce7a8cb939e295b1e7be835a1112c3b9a7f047a5a"
 
+[[package]]
+name = "unicode-width"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0edd1e5b14653f783770bce4a4dabb4a5108a5370a5f5d8cfe8710c361f6c8b"
+
 [[package]]
 name = "url"
 version = "2.3.1"
@@ -802,6 +828,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"

crates/ide/src/ide/mod.rs

@@ -14,7 +14,10 @@ mod syntax_highlighting;
 use crate::base::SourceDatabaseStorage;
 use crate::def::DefDatabaseStorage;
 use crate::ty::TyDatabaseStorage;
-use crate::{Change, Diagnostic, FileId, FilePos, FileRange, WorkspaceEdit};
+use crate::{
+    Change, Diagnostic, FileId, FilePos, FileRange, FileSet, SourceRoot, VfsPath, WorkspaceEdit,
+};
+use nix_interop::DEFAULT_IMPORT_FILE;
 use salsa::{Database, Durability, ParallelDatabase};
 use smol_str::SmolStr;
 use std::fmt;
@@ -73,6 +76,21 @@ impl AnalysisHost {
         Self::default()
     }
 
+    pub fn new_single_file(src: &str) -> (Self, FileId) {
+        let mut change = Change::default();
+        let file = FileId(0);
+        change.change_file(file, src.into());
+        let mut file_set = FileSet::default();
+        file_set.insert(
+            file,
+            VfsPath::new(format!("/{DEFAULT_IMPORT_FILE}")).unwrap(),
+        );
+        change.set_roots(vec![SourceRoot::new_local(file_set, Some(file))]);
+        let mut this = Self::new();
+        this.apply_change(change);
+        (this, file)
+    }
+
     pub fn snapshot(&self) -> Analysis {
         Analysis {
             db: self.db.snapshot(),

crates/nil/Cargo.toml

@@ -8,6 +8,7 @@ rust-version = "1.66"
 [dependencies]
 anyhow = "1.0.68"
 argh = "0.1.10"
+codespan-reporting = "0.11.1"
 crossbeam-channel = "0.5.6"
 ide = { path = "../ide" }
 indexmap = "1.9.1"

crates/nil/src/main.rs

@@ -1,8 +1,11 @@
+use anyhow::Context;
 use argh::FromArgs;
+use ide::AnalysisHost;
 use lsp_server::Connection;
 use std::path::PathBuf;
 use std::sync::Arc;
 use std::{env, fs, io, process};
+use text_size::TextRange;
 use tracing_subscriber::fmt::writer::BoxMakeWriter;
 use tracing_subscriber::EnvFilter;
 
@@ -17,6 +20,27 @@ struct Args {
     /// print the version and exit
     #[argh(switch)]
     version: bool,
+    #[argh(subcommand)]
+    subcommand: Option<Subcommand>,
+}
+
+#[derive(Debug, FromArgs)]
+#[argh(subcommand)]
+enum Subcommand {
+    Diagnostics(DiagnosticsArgs),
+}
+
+#[derive(Debug, FromArgs)]
+#[argh(subcommand, name = "diagnostics")]
+/// Check and print diagnostics for a file.
+/// Exit with non-zero code if there are any diagnostics.
+/// WARNING: The output format is for human and should not be relied on.
+struct DiagnosticsArgs {
+    /// nix file to check, or read from stdin for `-`.
+    /// NB. You need `--` before `-` for paths starting with `-`,
+    /// to disambiguous it from flags.
+    #[argh(positional)]
+    path: PathBuf,
 }
 
 fn main() {
@@ -31,6 +55,12 @@ fn main() {
         return;
     }
 
+    if let Some(subcommand) = args.subcommand {
+        return match subcommand {
+            Subcommand::Diagnostics(args) => main_diagnostics(args),
+        };
+    }
+
     setup_logger();
 
     let (conn, io_threads) = Connection::stdio();
@@ -44,6 +74,70 @@ fn main() {
     }
 }
 
+fn main_diagnostics(args: DiagnosticsArgs) {
+    use codespan_reporting::diagnostic::{Diagnostic, Label, Severity};
+    use codespan_reporting::files::SimpleFiles;
+    use codespan_reporting::term;
+    use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
+
+    let ret = (|| -> anyhow::Result<bool> {
+        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");
+        if diags.is_empty() {
+            return Ok(true);
+        }
+
+        let mut files = SimpleFiles::new();
+        let cr_file = files.add(path.display().to_string(), src);
+
+        let writer = StandardStream::stdout(ColorChoice::Auto);
+        let config = codespan_reporting::term::Config::default();
+
+        for diag in diags {
+            let severity = match diag.severity() {
+                ide::Severity::IncompleteSyntax | ide::Severity::Error => Severity::Error,
+                ide::Severity::Warning => Severity::Warning,
+            };
+
+            let to_range = |range: TextRange| usize::from(range.start())..usize::from(range.end());
+
+            let labels = std::iter::once(Label::primary(cr_file, to_range(diag.range)))
+                .chain(diag.notes.iter().map(|(frange, note)| {
+                    assert_eq!(frange.file_id, file, "Diagnostics are local");
+                    Label::secondary(cr_file, to_range(frange.range)).with_message(note)
+                }))
+                .collect();
+
+            let diag = Diagnostic::new(severity)
+                .with_code(diag.code())
+                .with_message(diag.message())
+                .with_labels(labels);
+
+            term::emit(&mut writer.lock(), &config, &files, &diag)?;
+        }
+        Ok(false)
+    })();
+    match ret {
+        Ok(true) => {}
+        Ok(false) => process::exit(1),
+        Err(err) => {
+            eprintln!("{err:#}");
+            process::exit(1);
+        }
+    }
+}
+
 fn setup_logger() {
     let file = env::var_os(LOG_PATH_ENV).and_then(|path| {
         let path = PathBuf::from(path);