Implement incremental linking and add DragonFly BSD VM build

.github/workflows/release.yml

@@ -360,7 +360,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        system: [freebsd, openbsd, netbsd]
+        system: [freebsd, openbsd, netbsd, dragonfly]
     steps:
       - uses: actions/checkout@v4
         with:
@@ -428,6 +428,23 @@ jobs:
           cp target/release/dcr "$ASSET"
           echo "BSD_ASSET=${ASSET}" >> "$GITHUB_ENV"
 
+      # --- DRAGONFLYBSD ---
+      - name: Build in DragonFly BSD VM
+        if: matrix.system == 'dragonfly'
+        uses: vmactions/dragonflybsd-vm@v1
+        with:
+          usesh: true
+          run: |
+            pkg install -y rust perl5 gmake
+            cargo build --release
+
+      - name: Prepare DragonFly BSD Artifact
+        if: matrix.system == 'dragonfly'
+        run: |
+          ASSET="dcr-x86_64-unknown-dragonfly-${{ needs.setup.outputs.version }}"
+          cp target/release/dcr "$ASSET"
+          echo "BSD_ASSET=${ASSET}" >> "$GITHUB_ENV"
+
       # --- UPLOAD TARGET ---
       - name: Upload BSD Asset to Release
         uses: softprops/action-gh-release@v2

src/core/builder/common.rs

@@ -316,6 +316,31 @@ pub fn needs_rebuild(source: &str, object: &str) -> bool {
     false
 }
 
+pub fn needs_link(objects: &[String], output_path: &str) -> bool {
+    let out_meta = match fs::metadata(output_path) {
+        Ok(m) => m,
+        Err(_) => return true,
+    };
+    let out_time = match out_meta.modified() {
+        Ok(t) => t,
+        Err(_) => return true,
+    };
+    for obj in objects {
+        let obj_meta = match fs::metadata(obj) {
+            Ok(m) => m,
+            Err(_) => return true,
+        };
+        let obj_time = match obj_meta.modified() {
+            Ok(t) => t,
+            Err(_) => return true,
+        };
+        if obj_time > out_time {
+            return true;
+        }
+    }
+    false
+}
+
 fn parse_d_file(content: &str) -> Vec<String> {
     let mut deps = Vec::new();
     let text = content.replace("\\\n", " ").replace("\\\r\n", " ");
@@ -418,6 +443,55 @@ mod tests {
         assert_eq!(result, "target/debug/obj/main.c.obj");
     }
 
+    #[test]
+    fn needs_link_no_output() {
+        let dir = temp_dir("link_no_out");
+        let obj1 = dir.join("test1.o");
+        let obj2 = dir.join("test2.o");
+        let out = dir.join("app");
+        fs::write(&obj1, "").unwrap();
+        fs::write(&obj2, "").unwrap();
+        let objs = vec![
+            obj1.to_string_lossy().to_string(),
+            obj2.to_string_lossy().to_string(),
+        ];
+        assert!(needs_link(&objs, &out.to_string_lossy()));
+    }
+
+    #[test]
+    fn needs_link_fresh() {
+        let dir = temp_dir("link_fresh");
+        let obj1 = dir.join("test1.o");
+        let obj2 = dir.join("test2.o");
+        let out = dir.join("app");
+        fs::write(&obj1, "").unwrap();
+        fs::write(&obj2, "").unwrap();
+        std::thread::sleep(std::time::Duration::from_millis(50));
+        fs::write(&out, "").unwrap();
+        let objs = vec![
+            obj1.to_string_lossy().to_string(),
+            obj2.to_string_lossy().to_string(),
+        ];
+        assert!(!needs_link(&objs, &out.to_string_lossy()));
+    }
+
+    #[test]
+    fn needs_link_stale() {
+        let dir = temp_dir("link_stale");
+        let obj1 = dir.join("test1.o");
+        let obj2 = dir.join("test2.o");
+        let out = dir.join("app");
+        fs::write(&obj1, "").unwrap();
+        fs::write(&out, "").unwrap();
+        std::thread::sleep(std::time::Duration::from_millis(50));
+        fs::write(&obj2, "").unwrap();
+        let objs = vec![
+            obj1.to_string_lossy().to_string(),
+            obj2.to_string_lossy().to_string(),
+        ];
+        assert!(needs_link(&objs, &out.to_string_lossy()));
+    }
+
     #[test]
     fn needs_rebuild_no_object() {
         let dir = temp_dir("rebuild_no_obj");

src/core/builder/gas.rs

@@ -43,6 +43,10 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
 
     if ctx.kind == "staticlib" {
         let lib_path = platform::lib_path(ctx.profile, ctx.project_name, ctx.target_dir);
+        if !common::needs_link(&objects, &lib_path) {
+            let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+            return Ok(elapsed);
+        }
         let archiver = ctx.archiver.unwrap_or(if cfg!(target_os = "windows") {
             "lib"
         } else {
@@ -105,6 +109,11 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
     } else {
         platform::bin_path(ctx.profile, &final_name, ctx.target_dir)
     };
+
+    if !common::needs_link(&objects, &out_path) {
+        let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+        return Ok(elapsed);
+    }
     cmd.arg("-o").arg(out_path);
 
     if ctx.verbose || std::env::var("DCR_DEBUG").is_ok() {

src/core/builder/msvc.rs

@@ -43,6 +43,10 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
 
     if ctx.kind == "staticlib" {
         let lib_path = platform::lib_path(ctx.profile, ctx.project_name, ctx.target_dir);
+        if !common::needs_link(&objects, &lib_path) {
+            let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+            return Ok(elapsed);
+        }
         let mut cmd = Command::new(ctx.archiver.unwrap_or("lib"));
         cmd.arg("/nologo").arg(format!("/OUT:{lib_path}"));
         for obj in &objects {
@@ -117,6 +121,11 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
     } else {
         platform::bin_path(ctx.profile, ctx.project_name, ctx.target_dir)
     };
+
+    if !common::needs_link(&objects, &out_path) {
+        let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+        return Ok(elapsed);
+    }
     cmd.arg(format!("/Fe:{out_path}"));
 
     if ctx.verbose || std::env::var("DCR_DEBUG").is_ok() {

src/core/builder/nasm.rs

@@ -43,6 +43,10 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
 
     if ctx.kind == "staticlib" {
         let lib_path = platform::lib_path(ctx.profile, ctx.project_name, ctx.target_dir);
+        if !common::needs_link(&objects, &lib_path) {
+            let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+            return Ok(elapsed);
+        }
         let archiver = ctx.archiver.unwrap_or(if cfg!(target_os = "windows") {
             "lib"
         } else {
@@ -105,6 +109,11 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
     } else {
         platform::bin_path(ctx.profile, &final_name, ctx.target_dir)
     };
+
+    if !common::needs_link(&objects, &out_path) {
+        let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+        return Ok(elapsed);
+    }
     cmd.arg("-o").arg(out_path);
 
     if ctx.verbose || std::env::var("DCR_DEBUG").is_ok() {

src/core/builder/unix_cc.rs

@@ -45,6 +45,10 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
 
     if ctx.kind == "staticlib" {
         let lib_path = platform::lib_path(ctx.profile, ctx.project_name, ctx.target_dir);
+        if !common::needs_link(&objects, &lib_path) {
+            let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+            return Ok(elapsed);
+        }
         let mut cmd = Command::new(ctx.archiver.unwrap_or("ar"));
         cmd.arg("rcs").arg(&lib_path);
         for obj in &objects {
@@ -106,6 +110,11 @@ pub fn build(ctx: &BuildContext) -> Result<f64, String> {
     } else {
         platform::bin_path(ctx.profile, &final_name, ctx.target_dir)
     };
+
+    if !common::needs_link(&objects, &out_path) {
+        let elapsed = ((start_time.elapsed().as_secs_f64() * 100.0).trunc()) / 100.0;
+        return Ok(elapsed);
+    }
     cmd.arg("-o").arg(out_path);
 
     if ctx.verbose || std::env::var("DCR_DEBUG").is_ok() {