From f82581a62a7b896f9119acf117525d73b4e94098 Mon Sep 17 00:00:00 2001
From: Amp <amp@ampcode.com>
Date: Tue, 15 Sep 2026 18:03:40 +0000
Subject: [PATCH] fix: skip scanner symlink cycles and map compile_batch panics

Library and source scanners no longer follow directory or file
symlinks, and skip target/.git/build trees. compile_batch reports
worker panics as CompileError instead of unwinding.

Amp-Thread-ID: https://ampcode.com/threads/T-01a0a631-cbad-764e-a59c-662f4c6e0902
Co-authored-by: Max Carter <undivisible@vk.com>
---
 src/compiler.rs | 11 ++++++++++-
 src/detector.rs | 24 +++++++++++++++++++++++-
 src/scanner.rs  | 39 +++++++++++++++++++++++++++++++++++++--
 3 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/src/compiler.rs b/src/compiler.rs
index a5fa25c..ae2b730 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -245,7 +245,16 @@ pub fn compile_batch(
                 scope.spawn(move || compile_to_c_with_lang(&path, &output_dir, lang))
             })
             .collect();
-        handles.into_iter().map(|h| h.join().unwrap()).collect()
+        handles
+            .into_iter()
+            .map(|h| {
+                h.join().unwrap_or_else(|_| {
+                    Err(CompileError::Io(std::io::Error::other(
+                        "compile_batch worker thread panicked",
+                    )))
+                })
+            })
+            .collect()
     })
 }
 
diff --git a/src/detector.rs b/src/detector.rs
index 305e293..45cb3ce 100644
--- a/src/detector.rs
+++ b/src/detector.rs
@@ -304,7 +304,15 @@ pub fn scan_directory(dir: &Path) -> Vec<(std::path::PathBuf, Language)> {
         if let Ok(entries) = std::fs::read_dir(dir) {
             for entry in entries.flatten() {
                 let path = entry.path();
-                if path.is_dir() {
+                let file_type = match entry.file_type() {
+                    Ok(ft) => ft,
+                    Err(_) => continue,
+                };
+                // Do not follow directory symlinks (avoids cycles and unexpected trees).
+                if file_type.is_symlink() {
+                    continue;
+                }
+                if file_type.is_dir() {
                     // Skip common non-source directories
                     let name = path.file_name().and_then(|n| n.to_str()).unwrap_or("");
                     if !matches!(
@@ -494,4 +502,18 @@ mod tests {
         assert_eq!(results.len(), 1);
         assert_eq!(results[0].1, Language::Zig);
     }
+
+    #[cfg(unix)]
+    #[test]
+    fn test_scan_directory_skips_symlinked_dirs() {
+        let dir = tempdir().unwrap();
+        let real = dir.path().join("real");
+        std::fs::create_dir(&real).unwrap();
+        std::fs::write(real.join("lib.c"), "").unwrap();
+        std::os::unix::fs::symlink(&real, dir.path().join("link")).unwrap();
+
+        let results = scan_directory(dir.path());
+        assert_eq!(results.len(), 1);
+        assert!(results[0].0.ends_with("lib.c"));
+    }
 }
diff --git a/src/scanner.rs b/src/scanner.rs
index 1454fe2..1922b8c 100644
--- a/src/scanner.rs
+++ b/src/scanner.rs
@@ -99,13 +99,33 @@ impl LibraryScanner {
             let entry = entry.map_err(|e| format!("Failed to read entry: {}", e))?;
             let path = entry.path();
 
-            if path.is_file() {
+            let file_type = match entry.file_type() {
+                Ok(ft) => ft,
+                Err(_) => continue,
+            };
+            if file_type.is_symlink() {
+                continue;
+            }
+            if file_type.is_file() {
                 if let Some(ext) = path.extension() {
                     if ext == "h" && !self.should_exclude(&path) {
                         headers.push(path);
                     }
                 }
-            } else if path.is_dir() && self.options.recursive {
+            } else if file_type.is_dir() && self.options.recursive {
+                let name = path.file_name().and_then(|n| n.to_str()).unwrap_or("");
+                if matches!(
+                    name,
+                    "target"
+                        | "node_modules"
+                        | ".git"
+                        | "build"
+                        | "dist"
+                        | "zig-cache"
+                        | "nimcache"
+                ) {
+                    continue;
+                }
                 self.scan_directory(&path, discoveries)?;
             }
         }
@@ -354,6 +374,21 @@ mod tests {
         assert!(headers[0].ends_with("api.h"));
     }
 
+    #[test]
+    fn test_scan_skips_target_and_git_dirs() {
+        let dir = tempdir().unwrap();
+        let target = dir.path().join("target");
+        fs::create_dir(&target).unwrap();
+        fs::write(target.join("generated.h"), "int skip(void);").unwrap();
+        fs::write(dir.path().join("api.h"), "int add(int a, int b);").unwrap();
+
+        let scanner = LibraryScanner::new(dir.path());
+        let discoveries = scanner.scan().unwrap();
+        assert_eq!(discoveries.len(), 1);
+        assert_eq!(discoveries[0].headers.len(), 1);
+        assert!(discoveries[0].headers[0].ends_with("api.h"));
+    }
+
     #[test]
     fn test_generate_all_creates_mod_rs() {
         let dir = tempdir().unwrap();