BINDGEN_EXTRA_CLANG_ARGS for command line mode issue-1723

Author: smurfd

src/lib.rs

@@ -1435,8 +1435,8 @@ impl Builder {
         self
     }
 
-    /// Generate the Rust bindings using the options built up thus far.
-    pub fn generate(mut self) -> Result<Bindings, ()> {
+    /// Generate the Rust bindings options
+    pub fn generate_options(&mut self) -> &Self {
         // Add any extra arguments from the environment to the clang command line.
         if let Some(extra_clang_args) =
             get_target_dependent_env_var("BINDGEN_EXTRA_CLANG_ARGS")
@@ -1451,7 +1451,7 @@ impl Builder {
 
         // Transform input headers to arguments on the clang command line.
         self.options.input_header = self.input_headers.pop();
-        self.options.extra_input_headers = self.input_headers;
+        self.options.extra_input_headers = self.input_headers.to_vec();
         self.options.clang_args.extend(
             self.options.extra_input_headers.iter().flat_map(|header| {
                 iter::once("-include".into())
@@ -1466,7 +1466,12 @@ impl Builder {
                     clang::UnsavedFile::new(&name, &contents)
                 }),
         );
+        self
+    }
 
+    /// Generate the Rust bindings using the options built up thus far.
+    pub fn generate(mut self) -> Result<Bindings, ()> {
+        self.generate_options();
         Bindings::generate(self.options)
     }
 
@@ -1475,7 +1480,7 @@ impl Builder {
     /// This is useful when debugging bindgen, using C-Reduce, or when filing
     /// issues. The resulting file will be named something like `__bindgen.i` or
     /// `__bindgen.ii`
-    pub fn dump_preprocessed_input(&self) -> io::Result<()> {
+    pub fn dump_preprocessed_input(&mut self) -> io::Result<()> {
         let clang =
             clang_sys::support::Clang::find(None, &[]).ok_or_else(|| {
                 io::Error::new(
@@ -1543,6 +1548,7 @@ impl Builder {
             "__bindgen.i"
         })?;
         io::copy(&mut preprocessed, &mut file)?;
+        self.generate_options();
 
         if child.wait()?.success() {
             Ok(())