5 files changed, 127 insertions, 4 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 9baebf643..3801fce23 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -25,7 +25,7 @@ use hir_ty::{
     autoderef, display::HirFormatter, expr::ExprValidator, method_resolution, ApplicationTy,
     Canonical, InEnvironment, Substs, TraitEnvironment, Ty, TyDefId, TypeCtor,
 };
-use ra_db::{CrateId, Edition, FileId};
+use ra_db::{CrateId, CrateName, Edition, FileId};
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AttrsOwner, NameOwner},
@@ -91,6 +91,10 @@ impl Crate {
         db.crate_graph()[self.id].edition
     }
 
+    pub fn display_name(self, db: &dyn HirDatabase) -> Option<CrateName> {
+        db.crate_graph()[self.id].display_name.as_ref().cloned()
+    }
+
     pub fn all(db: &dyn HirDatabase) -> Vec<Crate> {
         db.crate_graph().iter().map(|id| Crate { id }).collect()
     }
diff --git a/crates/rust-analyzer/src/bin/args.rs b/crates/rust-analyzer/src/bin/args.rs
index 3cf394bb4..f5981588a 100644
--- a/crates/rust-analyzer/src/bin/args.rs
+++ b/crates/rust-analyzer/src/bin/args.rs
@@ -35,6 +35,13 @@ pub(crate) enum Command {
         what: BenchWhat,
         load_output_dirs: bool,
     },
+    Diagnostics {
+        path: PathBuf,
+        load_output_dirs: bool,
+        /// Include files which are not modules. In rust-analyzer
+        /// this would include the parser test files.
+        all: bool,
+    },
     RunServer,
     Version,
 }
@@ -209,6 +216,38 @@ ARGS:
                 let load_output_dirs = matches.contains("--load-output-dirs");
                 Command::Bench { path, what, load_output_dirs }
             }
+            "diagnostics" => {
+                if matches.contains(["-h", "--help"]) {
+                    eprintln!(
+                        "\
+ra-cli-diagnostics
+
+USAGE:
+    rust-analyzer diagnostics [FLAGS] [PATH]
+
+FLAGS:
+    -h, --help              Prints help information
+        --load-output-dirs  Load OUT_DIR values by running `cargo check` before analysis
+        --all               Include all files rather than only modules
+
+ARGS:
+    <PATH>"
+                    );
+                    return Ok(Err(HelpPrinted));
+                }
+
+                let load_output_dirs = matches.contains("--load-output-dirs");
+                let all = matches.contains("--all");
+                let path = {
+                    let mut trailing = matches.free()?;
+                    if trailing.len() != 1 {
+                        bail!("Invalid flags");
+                    }
+                    trailing.pop().unwrap().into()
+                };
+
+                Command::Diagnostics { path, load_output_dirs, all }
+            }
             _ => {
                 eprintln!(
                     "\
diff --git a/crates/rust-analyzer/src/bin/main.rs b/crates/rust-analyzer/src/bin/main.rs
index 608f4f67b..7cfc44f01 100644
--- a/crates/rust-analyzer/src/bin/main.rs
+++ b/crates/rust-analyzer/src/bin/main.rs
@@ -39,6 +39,10 @@ fn main() -> Result<()> {
             cli::analysis_bench(args.verbosity, path.as_ref(), what, load_output_dirs)?
         }
 
+        args::Command::Diagnostics { path, load_output_dirs, all } => {
+            cli::diagnostics(path.as_ref(), load_output_dirs, all)?
+        }
+
         args::Command::RunServer => run_server()?,
         args::Command::Version => println!("rust-analyzer {}", env!("REV")),
     }
diff --git a/crates/rust-analyzer/src/cli.rs b/crates/rust-analyzer/src/cli.rs
index c9738d101..a865a7c7e 100644
--- a/crates/rust-analyzer/src/cli.rs
+++ b/crates/rust-analyzer/src/cli.rs
@@ -3,6 +3,7 @@
 mod load_cargo;
 mod analysis_stats;
 mod analysis_bench;
+mod diagnostics;
 mod progress_report;
 
 use std::io::Read;
@@ -12,6 +13,10 @@ use ra_ide::{file_structure, Analysis};
 use ra_prof::profile;
 use ra_syntax::{AstNode, SourceFile};
 
+pub use analysis_bench::{analysis_bench, BenchWhat, Position};
+pub use analysis_stats::analysis_stats;
+pub use diagnostics::diagnostics;
+
 #[derive(Clone, Copy)]
 pub enum Verbosity {
     Spammy,
@@ -60,9 +65,6 @@ pub fn highlight(rainbow: bool) -> Result<()> {
     Ok(())
 }
 
-pub use analysis_bench::{analysis_bench, BenchWhat, Position};
-pub use analysis_stats::analysis_stats;
-
 fn file() -> Result<SourceFile> {
     let text = read_stdin()?;
     Ok(SourceFile::parse(&text).tree())
diff --git a/crates/rust-analyzer/src/cli/diagnostics.rs b/crates/rust-analyzer/src/cli/diagnostics.rs
new file mode 100644
index 000000000..92664b415
--- /dev/null
+++ b/crates/rust-analyzer/src/cli/diagnostics.rs
@@ -0,0 +1,74 @@
+//! Analyze all modules in a project for diagnostics. Exits with a non-zero status
+//! code if any errors are found.
+
+use anyhow::anyhow;
+use ra_db::SourceDatabaseExt;
+use ra_ide::Severity;
+use std::{collections::HashSet, path::Path};
+
+use crate::cli::{load_cargo::load_cargo, Result};
+use hir::Semantics;
+
+pub fn diagnostics(path: &Path, load_output_dirs: bool, all: bool) -> Result<()> {
+    let (host, roots) = load_cargo(path, load_output_dirs)?;
+    let db = host.raw_database();
+    let analysis = host.analysis();
+    let semantics = Semantics::new(db);
+    let members = roots
+        .into_iter()
+        .filter_map(|(source_root_id, project_root)| {
+            // filter out dependencies
+            if project_root.is_member() {
+                Some(source_root_id)
+            } else {
+                None
+            }
+        })
+        .collect::<HashSet<_>>();
+
+    let mut found_error = false;
+    let mut visited_files = HashSet::new();
+    for source_root_id in members {
+        for file_id in db.source_root(source_root_id).walk() {
+            // Filter out files which are not actually modules (unless `--all` flag is
+            // passed). In the rust-analyzer repository this filters out the parser test files.
+            if semantics.to_module_def(file_id).is_some() || all {
+                if !visited_files.contains(&file_id) {
+                    let crate_name = if let Some(module) = semantics.to_module_def(file_id) {
+                        if let Some(name) = module.krate().display_name(db) {
+                            format!("{}", name)
+                        } else {
+                            String::from("unknown")
+                        }
+                    } else {
+                        String::from("unknown")
+                    };
+                    println!(
+                        "processing crate: {}, module: {}",
+                        crate_name,
+                        db.file_relative_path(file_id)
+                    );
+                    for diagnostic in analysis.diagnostics(file_id).unwrap() {
+                        if matches!(diagnostic.severity, Severity::Error) {
+                            found_error = true;
+                        }
+
+                        println!("{:?}", diagnostic);
+                    }
+
+                    visited_files.insert(file_id);
+                }
+            }
+        }
+    }
+
+    println!();
+    println!("diagnostic scan complete");
+
+    if found_error {
+        println!();
+        Err(anyhow!("diagnostic error detected"))
+    } else {
+        Ok(())
+    }
+}