Vendor dependencies for 0.3.0 release

vendor/bindgen-0.70.1/codegen/postprocessing/mod.rs

@@ -0,0 +1,57 @@
+use proc_macro2::TokenStream;
+use quote::ToTokens;
+use syn::{parse2, File};
+
+use crate::BindgenOptions;
+
+mod merge_extern_blocks;
+mod sort_semantically;
+
+use merge_extern_blocks::merge_extern_blocks;
+use sort_semantically::sort_semantically;
+
+struct PostProcessingPass {
+    should_run: fn(&BindgenOptions) -> bool,
+    run: fn(&mut File),
+}
+
+// TODO: This can be a const fn when mutable references are allowed in const
+// context.
+macro_rules! pass {
+    ($pass:ident) => {
+        PostProcessingPass {
+            should_run: |options| options.$pass,
+            run: |file| $pass(file),
+        }
+    };
+}
+
+const PASSES: &[PostProcessingPass] =
+    &[pass!(merge_extern_blocks), pass!(sort_semantically)];
+
+pub(crate) fn postprocessing(
+    items: Vec<TokenStream>,
+    options: &BindgenOptions,
+) -> TokenStream {
+    let items = items.into_iter().collect();
+    let require_syn = PASSES.iter().any(|pass| (pass.should_run)(options));
+
+    if !require_syn {
+        return items;
+    }
+
+    // This syn business is a hack, for now. This means that we are re-parsing already
+    // generated code using `syn` (as opposed to `quote`) because `syn` provides us more
+    // control over the elements.
+    // The `unwrap` here is deliberate because bindgen should generate valid rust items at all
+    // times.
+    let mut file = parse2::<File>(items).unwrap();
+
+    for pass in PASSES {
+        if (pass.should_run)(options) {
+            (pass.run)(&mut file);
+        }
+    }
+
+    file.into_token_stream()
+}