ir: Allow whitelisting non-recursively

Fixes rust-lang#429

Author: emilio

Cargo.lock

@@ -1155,15 +1155,15 @@ pub struct WhitelistedItemsIter<'ctx, 'gen>
 {
     ctx: &'ctx BindgenContext<'gen>,
 
-    // The set of whitelisted items we have seen. If you think of traversing
-    // whitelisted items like GC tracing, this is the mark bits, and contains
-    // both black and gray items.
+    /// The set of whitelisted items we have seen. If you think of traversing
+    /// whitelisted items like GC tracing, this is the mark bits, and contains
+    /// both black and gray items.
     seen: ItemSet,
 
-    // The set of whitelisted items that we have seen but have yet to iterate
-    // over and collect transitive references from. To return to the GC analogy,
-    // this is the mark stack, containing the set of gray items which we have
-    // not finished tracing yet.
+    /// The set of whitelisted items that we have seen but have yet to iterate
+    /// over and collect transitive references from. To return to the GC analogy,
+    /// this is the mark stack, containing the set of gray items which we have
+    /// not finished tracing yet.
     to_iterate: Vec<ItemId>,
 }
 
@@ -1181,12 +1181,14 @@ impl<'ctx, 'gen> Iterator for WhitelistedItemsIter<'ctx, 'gen>
         debug_assert!(self.seen.contains(&id));
         debug_assert!(self.ctx.items.contains_key(&id));
 
-        let mut sub_types = ItemSet::new();
-        id.collect_types(self.ctx, &mut sub_types, &());
+        if self.ctx.options().whitelist_recursively {
+            let mut sub_types = ItemSet::new();
+            id.collect_types(self.ctx, &mut sub_types, &());
 
-        for id in sub_types {
-            if self.seen.insert(id) {
-                self.to_iterate.push(id);
+            for id in sub_types {
+                if self.seen.insert(id) {
+                    self.to_iterate.push(id);
+                }
             }
         }
 

src/ir/context.rs

@@ -188,6 +188,15 @@ impl Builder {
         self
     }
 
+    /// Whether to whitelist types recursively or not. Defaults to true.
+    ///
+    /// See https://github.com/servo/rust-bindgen/issues/429 for different use
+    /// cases for this.
+    pub fn whitelist_recursively(mut self, doit: bool) -> Self {
+        self.options.whitelist_recursively = doit;
+        self
+    }
+
     /// Generate a C/C++ file that includes the header and has dummy uses of
     /// every type defined in the header.
     pub fn dummy_uses<T: Into<String>>(mut self, dummy_uses: T) -> Builder {
@@ -529,6 +538,9 @@ pub struct BindgenOptions {
     /// Wether to keep documentation comments in the generated output. See the
     /// documentation for more details.
     pub generate_comments: bool,
+
+    /// Wether to whitelist types recursively. Defaults to true.
+    pub whitelist_recursively: bool,
 }
 
 impl BindgenOptions {
@@ -574,6 +586,7 @@ impl Default for BindgenOptions {
             codegen_config: CodegenConfig::all(),
             conservative_inline_namespaces: false,
             generate_comments: true,
+            whitelist_recursively: true,
         }
     }
 }

src/lib.rs

@@ -46,6 +46,9 @@ pub fn builder_from_flags<I>(args: I)
                 .long("no-doc-comments")
                 .help("Avoid including doc comments in the output, see: \
                       https://github.com/servo/rust-bindgen/issues/426"),
+            Arg::with_name("no-recursive-whitelist")
+                .long("no-recursive-whitelist")
+                .help("Avoid whitelisting types recursively"),
             Arg::with_name("builtins")
                 .long("builtins")
                 .help("Output bindings for builtin definitions, e.g. \
@@ -279,6 +282,10 @@ pub fn builder_from_flags<I>(args: I)
         builder = builder.generate_comments(false);
     }
 
+    if matches.is_present("no-recursive-whitelist") {
+        builder = builder.whitelist_recursively(false);
+    }
+
     if let Some(opaque_types) = matches.values_of("opaque-type") {
         for ty in opaque_types {
             builder = builder.opaque_type(ty);

src/options.rs

@@ -0,0 +1,20 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(non_snake_case)]
+
+pub enum Bar {}
+
+#[repr(C)]
+#[derive(Debug, Copy)]
+pub struct Foo {
+    pub baz: *mut Bar,
+}
+#[test]
+fn bindgen_test_layout_Foo() {
+    assert_eq!(::std::mem::size_of::<Foo>() , 8usize);
+    assert_eq!(::std::mem::align_of::<Foo>() , 8usize);
+}
+impl Clone for Foo {
+    fn clone(&self) -> Self { *self }
+}

tests/expectations/tests/no-recursive-whitelisting.rs

@@ -0,0 +1,7 @@
+// bindgen-flags: --no-recursive-whitelist --whitelist-type "Foo" --raw-line "pub enum Bar {}"
+
+struct Bar;
+
+struct Foo {
+  struct Bar* baz;
+};