Make ir::BindgenContext::gen take ownership of self

`bindgen` follows a pipeline architecture, and we only ever generate bindings
once. By taking ownership of `self`, we can enforce this. We can also remove
checks inside `gen` for whether we have resolved type refs or not, since we now
know that we haven't because it is guaranteed to only be called the one time.

src/codegen/mod.rs

@@ -7,6 +7,8 @@ pub mod struct_layout;
 use self::helpers::attributes;
 use self::struct_layout::StructLayoutTracker;
 
+use super::BindgenOptions;
+
 use ir::analysis::HasVtable;
 use ir::annotations::FieldAccessorKind;
 use ir::comment;
@@ -3327,7 +3329,7 @@ impl CodeGenerator for ObjCInterface {
     }
 }
 
-pub fn codegen(context: &mut BindgenContext) -> Vec<quote::Tokens> {
+pub(crate) fn codegen(context: BindgenContext) -> (Vec<quote::Tokens>, BindgenOptions) {
     context.gen(|context| {
         let _t = context.timer("codegen");
         let counter = Cell::new(0);

src/ir/context.rs

@@ -1152,17 +1152,15 @@ impl BindgenContext {
 
     /// Enter the code generation phase, invoke the given callback `cb`, and
     /// leave the code generation phase.
-    pub fn gen<F, Out>(&mut self, cb: F) -> Out
+    pub(crate) fn gen<F, Out>(mut self, cb: F) -> (Out, BindgenOptions)
     where
         F: FnOnce(&Self) -> Out,
     {
         self.in_codegen = true;
 
-        if !self.collected_typerefs() {
-            self.resolve_typerefs();
-            self.compute_bitfield_units();
-            self.process_replacements();
-        }
+        self.resolve_typerefs();
+        self.compute_bitfield_units();
+        self.process_replacements();
 
         self.deanonymize_fields();
 
@@ -1189,9 +1187,8 @@ impl BindgenContext {
         self.compute_cannot_derive_hash();
         self.compute_cannot_derive_partialord_partialeq_or_eq();
 
-        let ret = cb(self);
-        self.in_codegen = false;
-        ret
+        let ret = cb(&self);
+        (ret, self.options)
     }
 
     /// When the `testing_only_extra_assertions` feature is enabled, this
@@ -1416,9 +1413,9 @@ impl BindgenContext {
     }
 
     /// Resolve a function with the given id.
-    /// 
+    ///
     /// Panics if there is no item for the given `FunctionId` or if the resolved
-    /// item is not a `Function`. 
+    /// item is not a `Function`.
     pub fn resolve_func(&self, func_id: FunctionId) -> &Function {
         self.resolve_item(func_id).kind().expect_function()
     }

src/lib.rs

@@ -858,7 +858,7 @@ impl Builder {
     }
 
     /// Set whether `Ord` should be derived by default.
-    /// We can't compute `Ord` without computing `PartialOrd`, 
+    /// We can't compute `Ord` without computing `PartialOrd`,
     /// so we set the same option to derive_partialord.
     pub fn derive_ord(mut self, doit: bool) -> Self {
         self.options.derive_ord = doit;
@@ -1475,7 +1475,7 @@ fn ensure_libclang_is_loaded() {
 /// Generated Rust bindings.
 #[derive(Debug)]
 pub struct Bindings {
-    context: BindgenContext,
+    options: BindgenOptions,
     module: quote::Tokens,
 }
 
@@ -1559,10 +1559,10 @@ impl Bindings {
             try!(parse(&mut context));
         }
 
-        let items = codegen::codegen(&mut context);
+        let (items, options) = codegen::codegen(context);
 
         Ok(Bindings {
-            context: context,
+            options: options,
             module: quote! {
                 #( #items )*
             }
@@ -1600,11 +1600,11 @@ impl Bindings {
             "/* automatically generated by rust-bindgen */\n\n".as_bytes(),
         )?;
 
-        for line in self.context.options().raw_lines.iter() {
+        for line in self.options.raw_lines.iter() {
             writer.write(line.as_bytes())?;
             writer.write("\n".as_bytes())?;
         }
-        if !self.context.options().raw_lines.is_empty() {
+        if !self.options.raw_lines.is_empty() {
             writer.write("\n".as_bytes())?;
         }
 
@@ -1614,9 +1614,10 @@ impl Bindings {
 
     /// Checks if rustfmt_bindings is set and runs rustfmt on the file
     fn rustfmt_generated_file(&self, file: &Path) -> io::Result<()> {
-        let _t = self.context.timer("rustfmt_generated_file");
+        let _t = time::Timer::new("rustfmt_generated_file")
+            .with_output(self.options.time_phases);
 
-        if !self.context.options().rustfmt_bindings {
+        if !self.options.rustfmt_bindings {
             return Ok(());
         }
 
@@ -1629,8 +1630,7 @@ impl Bindings {
 
         let mut cmd = Command::new(rustfmt);
 
-        if let Some(path) = self.context
-            .options()
+        if let Some(path) = self.options
             .rustfmt_configuration_file
             .as_ref()
             .and_then(|f| f.to_str())