Fix handling of anonymous names in Clang 16.

bindgen/ir/comp.rs

@@ -12,6 +12,7 @@ use super::ty::RUST_DERIVE_IN_ARRAY_LIMIT;
 use crate::clang;
 use crate::codegen::struct_layout::{align_to, bytes_from_bits_pow2};
 use crate::ir::derive::CanDeriveCopy;
+use crate::ir::item;
 use crate::parse::{ClangItemParser, ParseError};
 use crate::HashMap;
 use crate::NonCopyUnionStyle;
@@ -1422,7 +1423,9 @@ impl CompInfo {
 
                         // A declaration of an union or a struct without name
                         // could also be an unnamed field, unfortunately.
-                        if cur.spelling().is_empty() &&
+                        let mut spelling = cur.spelling();
+                        item::normalize_name_for_clang_16(&mut spelling);
+                        if spelling.is_empty() &&
                             cur.kind() != CXCursor_EnumDecl
                         {
                             let ty = cur.cur_type();

bindgen/ir/item.rs

@@ -2016,3 +2016,16 @@ impl<'a> NameOptions<'a> {
         self.item.real_canonical_name(self.ctx, self)
     }
 }
+
+/// Normalizes names so that we can handle them identically in Clang 16 and earlier versions.
+///
+/// In Clang 16, anonymous names have names like `(anonymous union at foo.c:16)`, whereas in earlier
+/// versions of Clang they were the empty string. This function normalizes all such names to the
+/// empty string so that we can handle them identically.
+pub fn normalize_name_for_clang_16(name: &mut String) {
+    // This may seem fragile, but ")" is not a valid character in C identifiers, so it should
+    // actually be a reasonably robust check.
+    if name.ends_with(")") {
+        name.truncate(0);
+    }
+}

bindgen/ir/ty.rs

@@ -14,6 +14,7 @@ use super::template::{
 };
 use super::traversal::{EdgeKind, Trace, Tracer};
 use crate::clang::{self, Cursor};
+use crate::ir::item;
 use crate::parse::{ClangItemParser, ParseError, ParseResult};
 use std::borrow::Cow;
 use std::io;
@@ -1112,6 +1113,8 @@ impl Type {
                         }
                     }
 
+                    item::normalize_name_for_clang_16(&mut name);
+
                     TypeKind::Enum(enum_)
                 }
                 CXType_Record => {
@@ -1132,6 +1135,8 @@ impl Type {
                         }
                     }
 
+                    item::normalize_name_for_clang_16(&mut name);
+
                     TypeKind::Comp(complex)
                 }
                 CXType_Vector => {