Add --allowlist-item (#2601)

* Add `allowlist_item` method and flag

* Add `allowlist_item` basic functionality

* Add test

* Update changelog

Author: pvdrz

CHANGELOG.md

@@ -172,6 +172,8 @@
 
 ## Added
 - The `system` ABI is now supported as an option for the `--override-abi` flag.
+- The `allowlist_item` method and the `--allowlist-item` flag have been
+  included to filter items regardless or their kind.
 ## Changed
 - The `Clone` implementation for `_BindgenUnionField` has been changed to pass
   the `incorrect_clone_impl_on_copy_type` Clippy lint.

bindgen-cli/options.rs

@@ -258,6 +258,9 @@ struct BindgenCommand {
     /// Allowlist all contents of PATH.
     #[arg(long, value_name = "PATH")]
     allowlist_file: Vec<String>,
+    /// Allowlist all items matching REGEX. Other non-allowlisted items will not be generated.
+    #[arg(long, value_name = "REGEX")]
+    allowlist_item: Vec<String>,
     /// Print verbose error messages.
     #[arg(long)]
     verbose: bool,
@@ -471,6 +474,7 @@ where
         allowlist_type,
         allowlist_var,
         allowlist_file,
+        allowlist_item,
         verbose,
         dump_preprocessed_input,
         no_record_matches,
@@ -829,6 +833,10 @@ where
         builder = builder.allowlist_file(file);
     }
 
+    for item in allowlist_item {
+        builder = builder.allowlist_item(item);
+    }
+
     for arg in clang_args {
         builder = builder.clang_arg(arg);
     }

bindgen-tests/tests/expectations/tests/allowlist_item.rs

@@ -0,0 +1,17 @@
+// bindgen-flags: --allowlist-item 'Foo.*'
+
+struct Foo {
+  int field;
+};
+
+struct Foo FooNew(int value);
+
+#define FooDefault 0 
+
+struct Bar {
+  int field;
+};
+
+struct Foo BarNew(int value);
+
+#define BarDefault 0  

bindgen-tests/tests/headers/allowlist_item.h

@@ -2343,7 +2343,8 @@ If you encounter an error missing from this list, please file an issue or a PR!"
                     if self.options().allowlisted_types.is_empty() &&
                         self.options().allowlisted_functions.is_empty() &&
                         self.options().allowlisted_vars.is_empty() &&
-                        self.options().allowlisted_files.is_empty()
+                        self.options().allowlisted_files.is_empty() &&
+                        self.options().allowlisted_items.is_empty()
                     {
                         return true;
                     }
@@ -2373,6 +2374,11 @@ If you encounter an error missing from this list, please file an issue or a PR!"
 
                     let name = item.path_for_allowlisting(self)[1..].join("::");
                     debug!("allowlisted_items: testing {:?}", name);
+
+                    if self.options().allowlisted_items.matches(&name) {
+                        return true;
+                    }
+
                     match *item.kind() {
                         ItemKind::Module(..) => true,
                         ItemKind::Function(_) => {
@@ -2496,6 +2502,10 @@ If you encounter an error missing from this list, please file an issue or a PR!"
         for item in self.options().allowlisted_types.unmatched_items() {
             unused_regex_diagnostic(item, "--allowlist-type", self);
         }
+
+        for item in self.options().allowlisted_items.unmatched_items() {
+            unused_regex_diagnostic(item, "--allowlist-items", self);
+        }
     }
 
     /// Convenient method for getting the prefix to use for most traits in

bindgen/ir/context.rs

@@ -435,18 +435,19 @@ impl Builder {
 
 impl BindgenOptions {
     fn build(&mut self) {
-        const REGEX_SETS_LEN: usize = 27;
+        const REGEX_SETS_LEN: usize = 28;
 
         let regex_sets: [_; REGEX_SETS_LEN] = [
-            &mut self.allowlisted_vars,
-            &mut self.allowlisted_types,
-            &mut self.allowlisted_functions,
-            &mut self.allowlisted_files,
             &mut self.blocklisted_types,
             &mut self.blocklisted_functions,
             &mut self.blocklisted_items,
             &mut self.blocklisted_files,
             &mut self.opaque_types,
+            &mut self.allowlisted_vars,
+            &mut self.allowlisted_types,
+            &mut self.allowlisted_functions,
+            &mut self.allowlisted_files,
+            &mut self.allowlisted_items,
             &mut self.bitfield_enums,
             &mut self.constified_enums,
             &mut self.constified_enum_modules,
@@ -482,6 +483,7 @@ impl BindgenOptions {
                     "--allowlist-function",
                     "--allowlist-var",
                     "--allowlist-file",
+                    "--allowlist-item",
                     "--bitfield-enum",
                     "--newtype-enum",
                     "--newtype-global-enum",

bindgen/lib.rs

@@ -345,6 +345,23 @@ options! {
         },
         as_args: "--allowlist-file",
     },
+    /// Items that have been allowlisted and should appear in the generated code.
+    allowlisted_items: RegexSet {
+        methods: {
+            regex_option! {
+                /// Generate bindings for the given item, regardless of whether it is a type,
+                /// function, module, etc.
+                ///
+                /// This option is transitive by default. Check the documentation of the
+                /// [`Builder::allowlist_recursively`] method for further information.
+                pub fn allowlist_item<T: AsRef<str>>(mut self, arg: T) -> Builder {
+                    self.options.allowlisted_items.insert(arg);
+                    self
+                }
+            }
+        },
+        as_args: "--allowlist-item",
+    },
     /// The default style of for generated `enum`s.
     default_enum_style: EnumVariation {
         methods: {