Introduce ParseCallbacks::header_file

bindgen/callbacks.rs

@@ -99,6 +99,9 @@ pub trait ParseCallbacks: fmt::Debug {
         None
     }
 
+    /// This will be called on every input file with the path of the file.
+    fn input_file(&self, _filename: &str) {}
+
     /// This will be called on every file inclusion, with the full path of the included file.
     fn include_file(&self, _filename: &str) {}
 

bindgen/lib.rs

@@ -325,6 +325,11 @@ impl Builder {
                 .map(String::into_boxed_str),
         );
 
+        for header in &self.options.input_headers {
+            self.options
+                .for_each_callback(|cb| cb.input_file(header.as_ref()));
+        }
+
         // Transform input headers to arguments on the clang command line.
         self.options.clang_args.extend(
             self.options.input_headers
@@ -566,6 +571,10 @@ impl BindgenOptions {
             .collect()
     }
 
+    fn for_each_callback(&self, f: impl Fn(&dyn callbacks::ParseCallbacks)) {
+        self.parse_callbacks.iter().for_each(|cb| f(cb.as_ref()));
+    }
+
     fn process_comment(&self, comment: &str) -> String {
         let comment = comment::preprocess(comment);
         self.parse_callbacks
@@ -1232,9 +1241,50 @@ fn get_target_dependent_env_var(
 ///     .generate();
 /// ```
 #[derive(Debug)]
-pub struct CargoCallbacks;
+pub struct CargoCallbacks {
+    rerun_on_input_files: bool,
+}
+
+/// Create a new `CargoCallbacks` value with [`CargoCallbacks::rerun_on_input_files`] disabled.
+///
+/// This constructor has been deprecated in favor of [`CargoCallbacks::new`] where
+/// [`CargoCallbacks::rerun_on_input_files`] is enabled by default.
+#[deprecated = "Use `CargoCallbacks::new()` instead. Please, check the documentation for further information."]
+pub const CargoCallbacks: CargoCallbacks = CargoCallbacks {
+    rerun_on_input_files: false,
+};
+
+impl CargoCallbacks {
+    /// Create a new `CargoCallbacks` value.
+    pub fn new() -> Self {
+        Self {
+            rerun_on_input_files: true,
+        }
+    }
+
+    /// Whether Cargo should re-run the build script if any of the input files has changed.
+    ///
+    /// This option is enabled by default. Unless the deprecated [`const@CargoCallbacks`] constructor is
+    /// used.
+    pub fn rerun_on_input_files(mut self, doit: bool) -> Self {
+        self.rerun_on_input_files = doit;
+        self
+    }
+}
+
+impl Default for CargoCallbacks {
+    fn default() -> Self {
+        Self::new()
+    }
+}
 
 impl callbacks::ParseCallbacks for CargoCallbacks {
+    fn input_file(&self, filename: &str) {
+        if self.rerun_on_input_files {
+            println!("cargo:rerun-if-changed={}", filename);
+        }
+    }
+
     fn include_file(&self, filename: &str) {
         println!("cargo:rerun-if-changed={}", filename);
     }